The Marginal Product of Labour Can Be Defined as (Where $\Delta$

Multiple Choice

The marginal product of labour can be defined as (where $\Delta$ denotes 'change') :

A) $\Delta$ output/ $\Delta$ labour
B) $\Delta$ labour/ $\Delta$ output
C) $\Delta$ profit/ $\Delta$ labour
D) $\Delta$ abour/ $\Delta$ total cost