Answer:
Preterite
Explanation:
The sentence translates as "Yesterday, my cousins _____ 15,000 pesos".
A verb from the preterite verb tense, indicating a punctual event in the past.
We know for sure it's in the past because the sentence starts with 'Ayer' - "Yesterday".
We assume it's punctual because it involves something about money.... a money transaction is usually punctual, it's not a mood or a description of a situation.
Unless you have a specific verb to go with that sentence, the verb could be:
(to pay): pagar -> pagaron
(to lose): perder -> perdieron
(to lend): prestar -> prestaron
and so on...
