Geometry

Question Analysis：
Tests recognition of a sufficient condition for a parallelogram.

Key Concept Explanation:
If both pairs of opposite sides are congruent, the figure is a parallelogram.

Step-by-Step Solution：
AB ≅ CD and AD ≅ BC → both opposite sides are congruent → parallelogram.

Option Analysis：
A – Trapezoid: Only one pair of parallel sides. ✖
B – Parallelogram: Matches condition. ✔
C – Squa...