Answer:
b. 63
Explanation:
A Parallelogram is known to be a flat shape quadrilateral which has four opposite sides Each two opposite sides are parallel and are equal in length. The opposite angles are equal.
The above answer is correct because opposite angles of a parallelogram are equal:
m∠CDA = m∠ABC
where m∠CDA = 63
∴ m∠ABC = 63 (answer)