“Bear out” means if someone or something bears a person out or bears out what that person is saying, they support what that person is saying.
Hence option A is the correct answer because “support” means bear all or part of the weight of, here the cause. Hence it is correct.
“Crush” means to violently subdue.
“Over throw” means to remove forcibly from power.
“Endure” means to suffer patiently.
“Destroy” means to ruin.
Hence from the above meanings, option A is the correct answer.