Which load balancing strategy does the Application Gateway implement? Select one.

Group of answer choices

Distributes requests to each available server in a backend pool in turn, round$-$robin.

Distributes requests to the server in the backend pool with the lightest load.

Uses one server in the backend pool until that server reaches $50\%$ load, then moves to the next server.

Polls each server in the backend pool in turn, and sends the request to the first server that responds.