Answer:
third option
Step-by-step explanation:
The n th term of 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
[tex]\frac{1}{4}[/tex] [tex](2)^{k-1}[/tex] ← is in this form
with a₁ = [tex]\frac{1}{4}[/tex] and r = 2
