Is the polygon ABCD a trapezium?
(I) It has a pair of parallel sides.
(II) Two of its sides are equal in length.

A

if the statement I alone is sufficient to answer the question.

B

if the statement II alone is sufficient to answer the question.

C

if both the statements I and II are sufficient to answer the question but neither statement alone is sufficient

D

it both the statements I and II together are not sufficient to answer the question and additional data is required.