Constant Returns to Scale Occur Whenever All Factors of Production

Constant returns to scale occur whenever all factors of production in an economic system increase in the same proportion and:

A) output increases by an amount greater than the proportionate increase in all inputs.
B) output increases by an amount less than the proportionate increase in all inputs.
C) output increases by an amount equal to the proportionate increase in all inputs.
D) inputs increase by an amount less than the proportionate increase in output.