The height of the net in the center of the tennis court is

2 feet 10 inches
2 feet 11 inches
2 feet 1 inch
3 feet 6 inches

The correct answer is: A. 2 feet 10 inches.

The net is 3 feet 6 inches high at the posts, but it is 2 feet 10 inches high in the center. This is to ensure that the ball can pass over the net without hitting it too high.

Option B is incorrect because the net is not 2 feet 11 inches high in the center.

Option C is incorrect because the net is not 2 feet 1 inch high in the center.

Option D is incorrect because the net is not 3 feet 6 inches high in the center.