Final answer:
Deleterious germ-line mutations are typically lost from a population through natural selection. They are removed because they decrease an organism's chances of survival and reproduction, despite being a critical source of genetic variation. The correct option is B. be lost from a population.
Step-by-step explanation:
Germ-line mutations that are deleterious are likely to be lost from a population. This occurs through the process of natural selection, where harmful mutations are removed by selection and are usually found in very low frequencies that match the mutation rate. Occasionally, some deleterious mutations may be maintained in a population due to factors like genetic drift or nonrandom mating, which can affect allele frequencies.
However, generally speaking, if a mutation is detrimental to the organism's survival and ability to reproduce, it will not persist in the population over time. It is important to note that mutation is the ultimate source of genetic variation in all populations, providing new alleles that can either be advantageous, disadvantageous, or neutral. The correct option is B. be lost from a population.