"In the supermarket."
Translation:En el supermercado.
If you take care to spell the word correctly, you won't lose a life. So I would suggest that the goal is to encourage you to take care to check before submitting the answer.
Also, if you use the web browser version you will get an incorrect answer, but you won't lose a life as the 'lives' system is not implemented. This is a far superior experience in my opinion.
Every noun in Spanish is either masculine (el) or feminine (la)
El mercado, el supermercado La caja (the cash register), la panadería (the bakery)
The definite article, indefinite article, and the adjectives must math the noun for gender and number (one or more than one).
La supermercado is flat out wrong. It is el supermercado. El and La are not interchangeable.