Mi amigoel mejor jugador de la universidad

es

Explanation:

I think you are asking the answer to the blank. When we translate this sentence, it will be "My friend ___ the best player in college." The only verb that makes sense is the conjugation is, which is the conjugated form of the verb to be in 3rd person singular. There are 2 verbs that mean to be in Spanish, ser and estar. We will use ser because estar is more used to describe how you are feeling. The 3rd person singular conjugation for ser is es. Hope this helps!