A Short-Run Production Function Was Estimated As $Q = - 0.002 L ^ { 3 } + 0.16 L ^ { 2 }$

Multiple Choice

A short-run production function was estimated as $Q = - 0.002 L ^ { 3 } + 0.16 L ^ { 2 }$ At 60 units of labor,what is marginal product?

A) 4.1
B) 1.2
C) 6.3
D) 2.4
E) -2.4