Natural selection favors survival traits in changing environments

Steps:

• Recall natural selection: process where organisms with advantageous traits survive and reproduce more, passing traits to offspring.
• Evaluate options: identify if trait arises from environmental pressures or human intervention.
• Check for resistance or adaptation to natural threats versus bred changes.
• Select option showing evolution via survival advantage without human design.

Why C is correct:

• Insecticide resistance evolves through natural selection, as mosquitoes with genetic mutations survive chemical exposure, reproduce, and increase resistant populations (Darwin's survival of the fittest principle).

Why the others are wrong:

• A: Friendly dogs result from artificial selection by humans breeding for desired traits.
• B: Seedless grapes are created through selective breeding, not environmental adaptation.
• D: Pleasant-tasting onions come from human-directed crop breeding for palatability.

Final answer: C