If one effect of a genetic mutation contributes substantially to survival of a species, that mutation will be favored in natural selection. In addition, if a mutation is favored in natural selection, that means at least one effect of that mutation contributes substantially to survival of a species.

The rules above are subject to one exception — when the effect of traits that are carried along with the genetic mutation are so negative that they cancel out the benefits of a mutation, the mutation won’t be favored.

There’s no clear inference to draw. We just need to understand the complicated rules in the stimulus accurately. The correct answer will be something that contradicts what we know, since this is a Must Be False question.