When mucus is released from a goblet cell in the trachea, the following events occur. In what order do these events happen?
- A$1 \rightarrow 4 \rightarrow 2 \rightarrow 3$
- B$1 \rightarrow 4 \rightarrow 3 \rightarrow 2$
- C$4 \rightarrow 1 \rightarrow 2 \rightarrow 3$
- D$4 \rightarrow 1 \rightarrow 3 \rightarrow 2$