When Capital Increases By $\Delta$ K Units and Labour Increases By $\Delta$

When capital increases by $\Delta$ K units and labour increases by $\Delta$ L units,output ( $\Delta$ Y) increases by:

A) $\Delta$ K + $\Delta$ L units.
B) MPL + MPK units.
C) (MPK × $\Delta$ K) + (MPL × $\Delta$ L) units.
D) (MPL × $\Delta$ K) + (MPK × $\Delta$ K) units.