Let be the set of all straight lines in the Euclidean plane. Two lines and are said to be related by the relation iff is parallel to Then the relation is
Equivalence
Explanation for the correct option:
Finding the the relation :
In co-ordinate plane.
Consider three lines
Therefore hence is reflexive
If then this implies that hence is symmetric and
If hence is transitive
Hence the relation is symmetric, reflexive and transitive. Therefore it is an equivalence relation.
Therefore, the correct answer is option (D).