Question

2.- "When ______ you eat that cake?"
- "I ______ it 30 minutes ago!"

A) do / eaten
B) does / ate
C) did / ate
D) will / will eat
E) would / did

Answer 1

Letra C
'Did' é usado para fazer perguntas do passado, e 'ate' é a forma passada de 'eat'. Podemos ver que a frase quer o passado pois 'ago' é do passado.

Answer 2

Letter "C"

Because "did" works as an auxiliar verb from the past tense. That's why we need to reply setting the verb in the past as well. In this case "eat" is an irregular verb and its past tense is "ate". 

;)