In general, which of the following implies that eventually marginal costs will increase as a firm produces more

In general, which of the following implies that eventually marginal costs will increase as a firm produces more

output? 

A) The law of diminishing returns.

B) A production function displaying increasing returns to scale.

C) Profit maximizing behavior by the firm.

D) The law of equi-marginal returns.

If the quantities of all inputs are increased by thirty percent and output expands by twenty-five percent, then the firm is experiencing:

A) constant returns to scale.

B) increasing returns to scale.

C) decreasing returns to scale.

D) no returns to scale.