The production function Q=KL exhibits

A) increasing returns to scale.

B) constant returns to scale.

C) decreasing returns to scale.

D) undefined returns to scale.

An input demand curve represents

A) how the cost-minimizing amount of input varies with the level of output.

B) how the cost-minimizing output varies with an input's price.

C) how the cost-minimizing amount of input changes with the input's price.

D) how the cost-minimizing output varies with the output price.

When the price of all inputs increase by the same percentage,

A) the firm's total cost curve will rotate upward by a higher percentage if the firm's production technology exhibits decreasing returns to scale.

B) the firm's total cost curve will rotate upward by the same percentage.

C) the firm's total cost curve will rotate upward by a higher percentage if the firm's production technology exhibits increasing returns to scale.

D) the firm's total cost curve will remain unchanged since the cost-minimizing combination of inputs is unchanged.

Please explain why for these!