Assume the Capital-Labour Ratio Remains Constant

Assume the capital-labour ratio remains constant.If investment increases at a constant rate,real GDP per worker will increase ________,and if total factor productivity increases at a constant rate,real GDP per worker will increase ________.

A) at an increasing rate; at an increasing rate
B) at a constant rate; at an increasing rate
C) at a constant rate; at a decreasing rate
D) at a decreasing rate; at a constant rate