Question regarding cost minimization (economics)

[keep_running]

[question removed by admin]
I thought the answer is B, but it is C. Shouldn’t we employ more skilled workers to even the MP/P ratios between skilled and unskilled workers?

 

[S2000magician]

The marginal product per dollar for unskilled workers is higher than the marginal product per dollar for skilled workers; use more unskilled workers.