49 According to the passage, which statement about hereidtary deafness in the ancient world is NOT accurate?
(A)To understand deafness in the ancient world, we need to take hereditary factors into consideration.
(B)There is clear evidence to show that inbreeding will definitely lead to deafness.
(C)Some families tended to have genes that caused deafness.
(D)It can be inferred that in-breeding in the ancient world would probably lead to serious consequences.