Answer:
B. Genetic variation
Step-by-step explanation:
New combinations of genes and alleles impart genetic variations to the offspring produced by sexual reproduction. These new gene combinations are produced during meiosis and fusion of male and female gametes. Some of these genetic variations become beneficial under certain conditions and increase the chances of survival of the species under unfavorable conditions.
Asexual reproduction includes a single parent. It does not involve the fusion of male and female gametes. Therefore, the progeny produced by asexual reproduction is genetically identical to the single parent and lack any genetic variations. The absence of genetic variations makes this progeny prone to be adversely affected by any biotic or abiotic disturbances such as diseases.