Why may melting the agarose be necessary during gel extraction?

Correct answer: To release the desired DNA fragment from the agarose matrix for recovery

After electrophoresis, the desired DNA fragment is physically trapped within the three-dimensional agarose matrix. To recover it, the excised gel slice is treated with an appropriate chaotropic or dissolving solution, often with controlled warming, so that the agarose structure breaks down or becomes fluid. The released DNA can then bind to a silica membrane or another purification material under suitable conditions, followed by washing and elution. Therefore option A is correct. Melting does not change DNA into protein and does not generally activate every enzyme. It also is not performed merely to remove the ladder; the target band itself must be released. Excessive heat or unsuitable conditions should be avoided because they can reduce DNA recovery or quality.