Let $f ( x ) = 8 x ^ { 5 } - 80 \ln x$

Multiple Choice

Let $f ( x ) = 8 x ^ { 5 } - 80 \ln x$ , for x > 0. Find the minimum value of f for x > 0.

A) $4 \left( 2 ^ { 5 } - 10 \ln 2 \right)$
B) $8 \left( 2 ^ { 5 } - 10 \ln 2 \right)$
C) 0
D) 16(1 - ln 2)