What Is the Overall Standard Free Energy Change for the Following

What is the overall standard free energy change for the following two reactions?
A + B $\to$ C
= $\Delta$ G₁
C + D $\to$ E
= $\Delta$ G₂

A) " $\Delta$ G₁ + $\Delta$ G₂"
B) " $\Delta$ G₁ - $\Delta$ G₂"
C) " $\Delta$ G₂ - $\Delta$ G₁"
D) " $\Delta$ G₁ $\Delta$ G₂"
E) " $\Delta$ G₁/ $\Delta$ G₂"