Voy a la playa para el sol.

a. pescar
b. patinar
c. bailar
d. tomar

Option D

Explanation: We must complete the sentence:

Voy a la playa para el sol.

In the Spanish sentence, the idea transmitted is that the person talking want to go to the beach to take a sunbath (looking at the options this is the one that makes sense)

if you want to say "I am going to take a sunbath" in Spanish, you should say "Voy a Tomar el sol" so the option that completes the sentence is D.

Voy a la playa para Tomar el sol.