¡Ne canso de decir que la palabra "sí" aquí requiere un acento!
Sra
Correct! The answer is "a. ahorrar" which means "to save" in English. To get the answer, you can look at the English translation of the sentence and identify the word that best fits the context. In this case, the sentence suggests that one should use air conditioning only when it's really hot in order to save energy. Therefore, the correct answer is "a. ahorrar."