If π f(t) = log₈(t⁷) π, find π f'(t) π. Use exact values.
a) π f'(t) = 7tln(8) π
b) π f'(t) = 7ln(t)ln(8) π
c) π f'(t) = 7tln(64) π
d) π f'(t) = 7ln(t)ln(64) π