The equation represents the overall reaction of an amine with an acid chloride. $\text{2CH}_3\text{CH}_2\text{NH}_2 + \text{CH}_3\text{CH}_2\text{COCl} \rightarrow \text{CH}_3\text{CH}_2\text{CONHCH}_2\text{CH}_3 + \text{CH}_3\text{CH}_2\text{NH}_3\text{Cl}$ The mechanism can be divided into four steps, listed below. Which of these steps are Brønsted-Lowry acid-base reactions?
- A1 and 3
- B3 and 4
- C3 only
- D4 only