Geometry

Question Analysis：
This question involves recognizing the properties that define a parallelogram.
The main focus is on the condition: “Both sets of opposite sides are congruent” and what geometric conclusion can be drawn from it.

Key Concept Explanation:
According to the properties of quadrilaterals in geometry:
A parallelogram is defined as a quadrilateral in which both pairs of opposite sides are parallel.
One way to prove a quadrilateral is a parallelogram is to show that both pairs of opposite sides are congruent. This is one of the standard sufficient conditions for a parallelogram.

Step-by-Step Solution：
The question gives a condition: both pairs of opposite sides are congruent.
According to the parallelogram conditions, this is sufficient to conclude the figure is a parallelogram.
We are not given any information about right angles or equal diagonals, so we cannot conclude that it is a rectangle or rhombus.
A trapezoid only has one pair of parallel sides, so this condition does not describe a trapezoid.
Therefore, the only guaranteed conclusion is that the quadrilateral is a parallelogram.

Option Analysis：
A) Rectangle – ❌ Incorrect. A rectangle requires all angles to be right angles, which we are not told.
B) Rhombus – ❌ Incorrect. A rhombus requires all four sides to be equal, which we are not told.
C) Parallelogram – ✅ Correct. This follows directly from the property: If both pairs of opp...