The correct answer is: A. has explained
The coach has explained the strengths of our opponents because our team has not played against them before. This is because the coach needs to make sure that the team is aware of the strengths of their opponents so that they can prepare for the game.
Option B is incorrect because the team has not played against the opponents before. Option C is incorrect because the coach is explaining the strengths of the opponents, not explaining why they are not playing. Option D is incorrect because the team will play against the opponents in the future. Option E is incorrect because the coach is explaining the strengths of the opponents, not explaining how to play against them.