As it was raining heavily, the manager suggested that his employee ___ a taxi to the meeting.

The subjunctive mood is used to express suggestions, recommendations, advice, demands, wishes, and doubts. It is also used to talk about hypothetical (imaginary) situations or something that is contrary to fact. examples-

1. They recommend that I arrive at school on time every day.

2. They wish that we arrive at school on time every day.