Correct : a

The phrase is "cope with varied environmental conditions."
• "Cope with" means to deal effectively with something difficult or challenging; to manage, handle, or contend with. In the context of life forms and environmental conditions, it implies the ability to survive and function despite difficulties presented by the environment.

Options:
• A) adopt to
    • "Adopt" means to take on or choose something as one's own (e.g., adopt a child, adopt a new strategy). The phrasing "adopt to" is not standard English and does not convey the meaning of dealing with a challenge.
• B) adapt to
    • "Adapt to" means to adjust to new conditions, to become suited to a new situation, or to modify oneself or something else to fit new circumstances. This meaning strongly aligns with how life forms survive in different environments, by undergoing changes or developing characteristics that allow them to deal with those conditions effectively.
• C) adept in
    • "Adept" is an adjective meaning very skilled or proficient at something. "Adept in" means skilled in a particular area (e.g., adept in coding). While life forms might be 'adept' at surviving, "adept in" is not a verb phrase that captures the active process of dealing with conditions, nor is it grammatically similar to "cope with."
• D) accept with
    • "Accept" means to receive something willingly or to agree to something. "Accept with" is not a common or natural phrasing in this context. While one might accept conditions, "cope with" implies a more active struggle or management of difficult situations, rather than simple acceptance.

Conclusion:
Comparing the options, "adapt to" is the closest in meaning to "cope with" as it correctly describes the process of adjusting and making oneself suitable to manage different environmental conditions.