Answer:
The correct answer is - the pack that preferentially kills mature, healthy moose.
Step-by-step explanation:
The birth rate is the number of individuals born in a population in a particular amount of time period. The birth rate can be determined by the individual born in a particular time period and that depends on how many healthy and viable individuals in a population can reproduce and produce new individuals.
Old and sicks are not the ones who can actively participate in reproduction and, however, if the number of healthy and mature individuals are killed there would be fewer newborns in the population.
Thus, the correct answer is the pack that preferentially kills mature, healthy moose.