Question

My friend has a sister, but he doesn't ... a brother.
a)has
b)have
c)had

Answer 1

My friend has a sister , but he doesn´t have a brother

is B)

Answer 2

b) have

A sentença está no tempo simple present, e a forma negativa da 3ª pessoa do singular em inglês do verbo 'to have' é "He doesn't have a brother".