Yes 1/4 is a rational number
For any quadrilateral to be a parallelogram
i) either both the pairs of opposite sides must be equal
ii) Both the pairs of opposite sides must be parallel
iii) Opposite pairs of angles must be equal
iv) Diagonals must bisect each other.
v) A pair of opposite sides must be parallel and equal
Here we are already given that AB || CD
So either we should be given that AD || BC
or we must be given that AB = CD
Here it is given AB = CD as an option.
So Option A) or the first option is the right answer that AB ≅CD is needed to prove ABCD is a parallelogram.
