Final answer:
In a family with 4 children, there are 4 combinations for having one boy and three girls, which can be represented as BGGG, GBGG, GGBG, GGGB. Thus, the answer is A. 4.
Step-by-step explanation:
To determine how many ways a family with 4 children could have one boy and three girls, we can use the concept of combinations. Since the order in which the children are born does not matter, we are looking for the number of combinations where we have 1 boy out of 4 children.
We can choose the boy in 4 ways (one for each child being the boy). Once the boy has been chosen, the other three positions will automatically be girls. Hence, there are 4 combinations for having one boy and three girls: BGGG, GBGG, GGBG, GGGB, where B represents a boy and G represents a girl.
Therefore, the answer is: A. 4.