Paragraph on nutrition glucose levels homeostasis

Rank the three variables in terms of how strongly they affect the "species" composition of the bacterial communities. place the variable with the weakest effect on the left and the variable with the strongest effect on the right.

Ineed to know why d is the correct answer asap

Afamily has a y-linked disease that affects the father. what is the chance of a male offspring inheriting the same disease? oa. 100% ob. 50% oc. 25% d. 0%