The Probability of a Couple Having Either a Boy or a Girl

The probability of a couple having either a boy or a girl is ½ . However, many families have more boys than girls and VICE VERSA. Why is the observed ratio of boys to girls in typical families different than the predicted ratio?

A) There is a large random sampling error due to the small size of families.
B) There is a small random sampling error due to the small size of families.
C) Humans are more heterozygous than is predicted by random sampling.
D) The sex of each child is determined independently.
E) Two of the answers are correct. There is a large random sampling error due to the small size of . human families and the sex of each child is determined independently.