Hey Sara, good question.
It may be helpful to work backwards for question 43.
We know that we end up with two children: both children have Turner syndrome (only one X chromosome, no Y chromosome) and one of those children is color-blind (a sex-linked recessive trait). From here, we can say that color-blindness must be carried on the X chromosome; if it was only carried on the Y chromosome, an individual with Turner syndrome could not be color blind as they do not have a Y chromosome.
Now, the parents. The father is color blind and must carry that trait on his X chromosome. The mother is healthy.
The final question remains: where do the nondisjunction events occur, namely which parental chromosomes are "lost" for which child.
A. "Nondisjunction occurred in the father for both children." If this were true, then neither child would be color-blind. We know the Y chromosome was "lost" (Turner syndrome). If the father's X chromosome was lost in both children, neither would be color-blind. This is not the correct answer.
B. "Nondisjunction occurred in the mother for both children." If this were true, then both children would be color-blind (both would inherit the father's X chromosome). However, we have been told that one child is color-blind. This is not the correct answer.
C. "Nondisjunction occurred in the mother for the colorblind child and in the father for the child with normal vision." In this case the color-blind child does not inherit the X chromosome from the mother, hence the color-blindness. The child with normal vision inherits the X chromosome from the father, hence the normal vision. To answer your question directly here: the color-blind child inherits the father's X chromosome because nondisjunction occurred in the mother; her X chromosomes are "lost". This is the correct answer.
D. "Nondisjunction occurred in the father for the colorblind child and in the mother for the child with normal vision." Here, the nondisjunction events are mixed up. If the nondisjunction occurred in the father, that color-blindness could not be passed on, if the nondisjunction occurred in the mother, the normal vision could not be passed on. This is not the correct answer.
I would recommend drawing out the chromosomes for each individual in questions like this. Being able to visualize how information is passed down generations is a powerful tool.
Good luck with your studies!