The equation indicates a reaction between aqueous hydrogen bromide and aqueous ammonia. $\text{HBr(aq)} + \text{NH}_3\text{(aq)} \rightarrow \text{NH}_4^+\text{(aq)} + \text{Br}^-\text{(aq)}$ Which statement explains the role of aqueous hydrogen bromide?
- AIt is a catalyst.
- BIt is a reducing agent.
- CIt is a proton acceptor.
- DIt is a proton donor.