Suppose a 1-Unit Increase in Labour, from 2 to 3

Multiple Choice

Suppose a 1-unit increase in labour, from 2 to 3 workers, increases output from 10 to 15 tea cups. The marginal product from the increase in the quantity of labour is

A) 1 tea cup.
B) 3 tea cups.
C) 10 tea cups.
D) 5 tea cups.
E) 15 tea cups.