For two statements p and q
p : A quadrilateral is a parallelogram,
q : The opposite sides are parallel. Then, the compound proposition, A quadrilateral is
a parallelogram if and only if the opposite sides are parallel' is represented by

• A

  $\mathrm{p}\vee \mathrm{q}$

• B

  $\mathrm{p}\to \mathrm{q}$

• C

  $\mathrm{p}\wedge \mathrm{q}$

• D

  $\mathrm{p}\leftrightarrow \mathrm{q}$