Let’s assume that angles B and C are not congruent. Then one angle measure must be greater than the other. If m∠B is greater than m∠C, then AC is greater than AB by the .

In a triangle, the side opposite the larger angle is longer than the side opposite the smaller angle. Since m∠B > m∠C, the opposite side AC is longer than the opposite side AB. This is the triangle parts relationship theorem, so the correct choice is B.

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