Answer:
B
Step-by-step explanation:
The explicit rule for a geometric sequence is
[tex]a_{n}[/tex] = a₁ [tex](r)^{n-1}[/tex]
where a₁ is the first term and r the common ratio
Here a₁ = 64 and r = [tex]\frac{a_{2} }{a_{1} }[/tex] = [tex]\frac{128}{64}[/tex] = 2 , then
[tex]a_{n}[/tex] = 64 [tex](2)^{n-1}[/tex] → B
