An author claims that "athletes caught using performance-enhancing drugs should be sentenced to prison." the author provides the following reason as support: in 2013, the tv show sport-zone surveyed 2,000 athletes. 73 percent admitted knowing a teammate who took performance-enhancing drugs. huang kroll, spokesperson for the international olympic committee, was interviewed during the program. "using illegal substances to gain an advantage is a huge issue," he explained. "unless stronger laws are passed—laws that result in prison rather than suspension from competition—the problem will continue to grow."
which choice best describes the reason the author provides?
a. it is effective. it supports the claim clearly and logically.
b. it is irrelevant. it discusses a fact that is off topic and does not support the claim.
c. it is unreliable. it does not give any details to prove that the source can be trusted.
d. it is unverified. it does not cite a source to show where the information was located.