Evaluate the following geometric sum. ∑₍ₖ₌₀₎¹⁹ ((7/8) ) ²ᵏ ∑₍ₖ₌₀₎¹⁹ ((7/8) ) ²ᵏ
A) 640/49
B) 49/640
C) 7/8
D) 8/7