Why is the respiratory pathway considered an amphibolic pathway?

Because it only involves the breakdown (catabolism) of substrates like carbohydrates, fats, and proteins. 

Because it is exclusively involved in the synthesis (anabolism) of complex molecules.

Because it plays a role in both the breakdown (catabolism) and synthesis (anabolism) of molecules.

Because it is unrelated to the processes of catabolism and anabolism in the cell.