Answer:
C
Step-by-step explanation:
The n th term formula of a geometric sequence is
[tex]a_{n}[/tex] = a [tex]r^{n-1}[/tex]
where a is the first term and r the common ratio
Using the second and fourth term, then
ar = 6 → (1)
ar³ = 54 → (2)
Divide (2) by (1)
[tex]\frac{ar^3}{ar}[/tex] = [tex]\frac{54}{6}[/tex] = 9
r² = 9 ⇒ r = [tex]\sqrt{9}[/tex] = 3 → C
