1. **State the problem:** Identify the type of polygon based on the given description. 2. **Given information:** The figure is a quadrilateral with two pairs of opposite sides parallel and equal in length. 3. **Recall polygon definitions:** - A **rhombus** is a parallelogram with all sides equal. - A **parallelogram** has two pairs of opposite sides parallel and equal. - An **isosceles trapezoid** has only one pair of parallel sides. - A **pentagon** has five sides. - A **rectangle** is a parallelogram with four right angles. 4. **Analyze the figure:** Since the figure has two pairs of opposite sides parallel and equal, it fits the definition of a parallelogram. 5. **Conclusion:** The polygon is a parallelogram. **Final answer:** B. parallelogram