Often the incorrect multiple choice answers are pretty nonsensical or seem to test the students' knowledge of English rather than the foreign language they are attempting to learn. I don't know if this is a glitch (because the wrong choices are randomly generated) or if it's built in to make these questions easier, but it's always annoyed me.
Alone, "é" pronounced like "eh" as in "elk" means "is" (as a conjugation of "ser") for third person "ele/ela" and you "vocé" (which is the more used version in Brazil, but knowing "tu" is probably good). The "e" alone sound like "ee" as in "eel" and means "and" in English. In a word, an accent over a vowel makes that syllable stressed. Also, like the word "vocé", the 'e' at the end would sound like "ee", but with the accent not only gets the stress (FYI, in Portuguese the stress is usually on the second to last syllable unless there is an accent mark), but the 'é' sounds like "eh" also.
Hope that helps... Full disclosure: I'm drunk, so I'm sorry if this isn't coherent.
In fact, você is written with an circumflex (^) on the e -> você.
I'm aware, that the written Portuguese also allows "vocé" (don't know where I read that), but since I'm learning, I want to write everything how it's supposed to :-) A friend of mine has told me, I can even cut você or também short (like vc and tb), but... See above ;-)
There is some debate about the correct usage of the words obrigado and obrigada. The usage indicated above is by far the most common way the words are used, that is, men always say obrigado and women always say obrigada. This usage implies that the word is being used as an adjective to describe the one speaking (literally meaning ‘obliged’).
Technically , it can be argued that the word obrigado, when used on its own to say ‘thank you’, is an interjection, not an adjective (in the same way that the word ‘hello’ is an interjection). Under this school of thought, both men and women should say obrigado regardless of whether they are addressing a man or a woman. Whilst this is probably the ‘correct’ usage, it is hardly ever encountered. Of course, if you are male, it doesn’t really matter as you would say obrigado anyway.
In some regions, particularly the Algarve, it is common for both men and women to use both obrigado and obrigada - switching between them depending on the gender of the person they are talking to. However, this usage does not seem to have any rational technical explanation! I would therefore recommend against that usage unless you happen to live in a region where the locals would be offended if you addressed them differently.
More and more Portuguese speakers as a statement are purposely choosing to say the opposite of what tradition dictates.
My impression is that people of both genders say "obrigade"
Actually what I hear is, "brigad[e]" where both the first and last vowels are swallowed.
Something I did not mention before though is that in print some, often organizations will often address people and sign off with the @ symbol in words to show "inclusion" to all (what they tell me...). So, Olá Amig@s and Obrigad@ would be seen instead. I once received an entire email where every single word that ended in "a" or "o" was changed to "@" which made it impossible to send through Google Translate! Ironically, it was for a language class. :D