Answer:
C). Age 60 is no longer as old as it used to be; healthy pilots can continue
flying safely for many years after 60.
Step-by-step explanation:
Counterclaims are primarily described as the claims that aim to offset or negate the original claim made by the author. It assists the author to provide another side of his argument and establish credibility.
As per the question, the third option asserts a claim which most appropriately negates the author's claim regarding the 'forced retirement of pilots over 60 years of age for the sake of passengers' safety.' It opposes this claim by asserting that age is not a factor but rather the health is and since 'age 60' has not remained similar to what it was earlier and thus, healthy pilots must be allowed to fly. This counterclaim logically denies the author's claim and offers a contrasting perspective to this claim regarding forced retirement. Hence, option C is the correct answer.