Answer:
From the given figure we get,
DC║AB
Explanation:
It is given that,
<DCB and <CBA are supplementary, that means
<DCB + <CBA = 180
If these two angles are on the same side of a traversal CB.
<DCB and CBA are same side interior angles.
CB is the traversal of AB and DC
Therefore we get DC║AB
The correct answer is DC║AB