Choose the most specific term that will make the following statement true. Do not assume anything more than the information given.

I am a ____ because my opposite sides are congruent and parallel.

square
rectangle
parallelogram
rhombus

All four choices fit the description.

As to your "most specific term", it probably refers to its main property.
Since a parallelogram is most often defined in terms of its parallel sides, that would be choice.