Answer:
If a noun ends in a vowel, simply add -s.
If a noun ends in a consonant, simply add -es.
If a noun ends in a -z, change the z to c before adding -es.
If a noun ends in ión, drop the written accent before adding -es.
If the plural refers to a mixed group, use the masculine.
If a noun ends in -z, add -es and change the z to c.
Explanation:
The answer is (a) because compro is bought in Spanish and in the question it says “yesterday he bought the gifts for his mother” so bought would be the best answer. (B) is to buy I guess like I will buy chicken. And (c) is like they bought chicken. How I know this is well I speak Spanish I hope this helps!
Are you trying to say "It is five in the afternoon."? Cause if you are it would be "Son las cinco de la tarde."