Answer: Option b: A las clases humildes
Explanation: Here we are talking about the text "El Son Cubano"
The question is:
" Who does the Son represent in his music?"
And the options are:
a) A los gobernadores (The governors)
b) A las clases humildes (The humble class)
c) A los africanos (The Africans)
d) A la burguesia (The bourgeoisie)
The Don represents the humble class in his music, so the correct answer is optio b; A las clases humildes