Which of the Following Series Are Geometric? (1) $5+5 a+5 a^{2}+5 a^{3}+\ldots$

Multiple Choice

Which of the following series are geometric? (1) $5+5 a+5 a^{2}+5 a^{3}+\ldots$
(2) $5+7 a+9 a^{2}+11 a^{3}+\ldots$
(3) $5+5 a k+5 a^{2} k^{2}+5 a^{3} k^{3}+\ldots$

A) (1) and (2)
B) (1) and (3)
C) (2) and (3)
D) (1) only
E) (2) only