A prism.
A trapezoid has one pair of parallel sides. They are opposite parallel lines of different lengths.
1 pair of parallel lines
It is possible for a hexagon to have one pair of parallel sides. A hexagon can have 0, 1, 2 or 3 pairs of parallel sides, and can have 0, 2, 3, 4, 5, or 6 parallel sides.
It has a 1 pair of opposite parallel sides of different lengths
A prism.
I think just the 2 end faces will be parallel, so the answer is 1 pair
Cylinder
-1
-1
-1
There is only 1 pair facing each other at each end
trapezoid
A tetrahedron.
A triangular base pyramid which is a tetrahedron has 4 faces, 6 edges and 4 vertices
1 pair of parallel line
A circle intersected by a pair of parallel lines.