$A \rightarrow D$ is an endothermic reaction occurring in $3$ steps (elementary).
$(i)$ $A \rightarrow B$ $\Delta H_{i} = +ve$
$(ii)$ $B \rightarrow C$ $\Delta H_{ii} = -ve$
$(iii)$ $C \rightarrow D$ $\Delta H_{iii} = -ve$
Which of the following graphs between potential energy ($y$-axis) vs reaction coordinate ($x$-axis) correctly represents the reaction profile of $A \rightarrow D$?

• A
  
• B
  
• C
  
• D