I've just found that GLM2, released 3 days before the test and said not to be covered in the terms test, contained the very same phrases as the question I got wrong in Section 6. While Statement 3 still seems wrong, Statement 2: an Antagonist must relax to allow a joint movement to occur (which I disregarded because they are used at the end of a movement when movement still occurs even though the antagonist is not relaxed), is taken right out of GLM2, and Statement 1 is indirectly confirmed as true.
Moral of the story: GLM 2 not being specifically examined doesn't mean they can't cover something on the musculoskeletal system (which is examined) from the GLM.
Moral of the story: GLM 2 not being specifically examined doesn't mean they can't cover something on the musculoskeletal system (which is examined) from the GLM.