Why Do Some Economists Say Labor Standards Are "Disguised Protection

Why do some economists say labor standards are "disguised protection"?

A) These standards favor nations that already have high labor standards and eliminate competition from nations who do not.
B) Nations with low labor standards often disguise the fact.
C) Focusing on labor standards disguises the fact that shoddy materials are often used in production.
D) Often children who should be in school go to work instead, and their participation is "disguised" as if an adult held the job.