What is the simplest form for 14/21

Option A is right

Step-by-step explanation:

Given that Amy has 3 children, and she is expecting another baby soon. Her first three children are girls.

The fourth baby is independent of first three babies

As regards child birth, each trial is independent of the other with probability for a girl or boy equally likely with p = 0.5 = q

Hence option A is right answer.

Option B is wrong because the previous 3 girls have nothing to affect the sex of 4th child

Option C is wrong, since each trial is independent

D) is wrong since even mom and dad cannot determine the sex of that baby, it is nature and pure chance.