If an Economy with Constant Returns to Scale Were to Double

Multiple Choice

If an economy with constant returns to scale were to double its physical capital stock,its available natural resources,and its human capital,but leave the size of the labor force the same,

A) its output would stay the same and so would its productivity.
B) its output and productivity would increase,but less than double.
C) its output and productivity would increase by more than double.
D) None of the above is correct.