An Aggregate Production Function Exhibits Constant Returns to Scale When

An aggregate production function exhibits constant returns to scale when a 1% increase in labour input

A) produces a 1% increase in output.
B) along with a 1% increase in capital produces the same amount of output.
C) along with a 1% increase in capital produces 1% more output.
D) along with a 1% decrease in capital produces the same amount of output.
E) induces a 1% increase in capital input.