おちゃ is not accepting green tea as an answer restaurant lesson 6
i know i am being picky, and tea will work just as well, but おちゃ or お茶 is usually green tea whereas こうちゃ or 紅茶 would be black tea.
either should accept tea as an answer, but おちゃ should also accept green tea.
お茶 is a word used to design any tea I think.
抹茶, 緑茶 are among the names and types of green tea. 緑茶（りょくちゃ）is the commonly used word.
On this article (in Japanese) http://www.ocha.tv/varieties/nihoncha_varieties/ it is written, "In Japan, most of the native teas (お茶) are green teas (緑茶)". 日本で生産されるお茶は、ほとんどが緑茶です。
Often you can be asked if you wish りょくちゃ(緑茶) or コーヒー in business meetings when you are the guest.