Robert Edwards was blinded in a traffic accident. He was also a little deaf _51_ old age. Last week, he was taking a walk near his home when a thunderstorm came. He hid _52_ the storm under a big tree and was struck by lightning. He was knocked _53_ the ground and woke up some 20 minutes _54_, lying face down in water in water below a tree. He went into the house and lay down in bed. A short time later, he awoke; his legs felt _55_ and he was trembling, but, when he opened his eyes, he could see the clock across the room fading in and out in front of him. When his wife entered, he _56_ her for the first time in nine years. Doctors _57_ that he had regained his sight and hearing obviously from the flash of lightning, but they were unable to explain that. The only _58_ explanation offered by one doctor was that, _59_ Edwards lost his sight as a result of trauma in a terrible accident, perhaps the only way it could be restored was by _60_ trauma.
__________
A. because
B. because of
C. as
D. since