answer a is a conclusion not a requirement B says if you don't excise equally it will damage your spine which lead to the passage

Reply: Hahha jesus Jeff keep it within the passage no outside info

Hi, all -

Bereket is correct about answer [A]. The statement "The muscles on opposite sides of the spine must pull equally in opposing directions to keep the back in proper alignment and protect the spine" describes a condition (back muscles pulling equally in opposite directions) that is NECESSARY for the desired result (keeping the back properly aligned). It does not state that the condition is SUFFICIENT. For example, the back may be misaligned for an unrelated reason (e.g., scoliosis) even though the muscles pull evenly. Therefore [A] is incorrect.

[C] is incorrect for much the same reason: the passage states that evenly pulling muscles are necessary for a straight back, but does not guarantee that evenly pulling muscles ALONE will have any positive effect at all.

[D] and [E] are easily eliminated, as the passage makes no reference either to the possibility of irreparable damage or to the need for daily exercise.

Thus [B], the only remaining answer, is correct. To verify this, notice that the passage states, roughly, that exercising muscles equally on both sides of the back is important because balanced muscle development is needed to keep the spine straight. This use of "because" is only legitimate if failure to exercise both sides equally leads to a significant risk of not having balanced muscle development.

Best,
Lyn