Answer:
Exactly one pair of opposite sides are parallel
Step-by-step explanation:
A trapezoid is a plane shape quadrilateral that has exactly one pair of its sides parallel.
The parallel sides must occur for it to be a trapezoid. If they do not, it is most likely another shape. They could occur between the top and bottom sides while the left and right sides remain non-parallel, or vice-versa.
The other options given do not fall into the description of a trapezoid, as its opposite sides and diagonals are not always congruent.
