Answer:
D. Increasing, because a > 1.
Explanation:
Given the logarithmic function:

We want to determine if the function is increasing or decreasing.
For any logarithm function:
• If the base, a > 1, the function is increasing over its entire domain.
,
• If the base, 0Thus, in our case, the function is increasing, because a > 1.
Option D is correct.