(b) Both Assertion and Reason are true but Reason is not a correct explanation of Assertion.
We know that is the equation of a line passing through the origin.
To check we will put the value of origin(0,0) in the equation:
LHS: y = 0
RHS : m(0) = 0
Since, LHS = RHS = 0
Therefore, origin satisfies the given equation.
Moreover, we know that is the equation of the line parallel to the -axis.
So, Assertion (A) and Reason (R) are true but Reason (R) is not a correct explanation of Assertion (A).