The Proportion of U

Multiple Choice

The proportion of U.S. births that result in a birth defect is approximately 1/33 according to the Centers for Disease Control and Prevention (CDC) . A local hospital randomly selects five births and lets the random variable X count the number not resulting in a defect. Assume the births are independent.
If 500 births were observed rather than only 5, what is the approximate probability that at least 490 do not result in birth defects?

A) 0.0000
B) 0.0901
C) 0.6371
D) 0.9105