Environments are constantly changing, so the organism must adapt. Sexual reproduction ensures genetic diversity in the progeny. If one or a few of the progeny have new traits that can help it survive in its changing environment, it is more likely to reach adulthood and reproduce.
If a species becomes isolated, or reproduces asexually it will not adapt to its environment, its traits will be exact copies of its parents and the species will eventually go extinct, that particular scenario only works in areas where the environment is stable and not subject to change.
I think the correct answer from the choices listed above is option D. Modern fishing practices threaten biodiversity mainly through the removal of community food supplies. When people remove a significant amount of fish, portions of the food web are disturbed and can affect a certain ecosystem.
<span>The genetic code is redundant, that means same genetic code is present in multiple times, in each cell. it acts as "nature's safety net" because if we happen to lose a part of our body or genetic material, it can be regenerated using the remaining part which contains the same genetic code.</span>
I'd say option B. Vitamin D and Calcium are needed to have strong bones, so it'd be most logical for this to be the answer.
Hope this helps!