According to the Per-Worker Production Function, How Will the Output

Multiple Choice

According to the per-worker production function, how will the output per worker be affected as the amount of capital per worker increases?  

A)  It will increase at an increasing rate. 
B)  It will first increase and then decrease. 
C)  It will decrease, but at an increasing rate. 
D)  It will increase, but at a decreasing rate.