JEE Math Practice Question

Let $\mathrm{X}=\mathbf{R} \times \mathbf{R}$. Define a relation R on X as : $$\left(a_1, b_1\right) R\left(a_2, b_2\right) \Leftrightarrow b_1=b_2$$ Statement I: $\quad \mathrm{R}$ is an equivalence relation. Statement II : For some $(\mathrm{a}, \mathrm{b}) \in \mathrm{X}$, the $\operatorname{set} \mathrm{S}=\{(x, y) \in \mathrm{X}:(x, y) \mathrm{R}(\mathrm{a}, \mathrm{b})\}$ represents a line parallel to $y=x$. In the light of the above statements, choose the correct answer from the options given below :

1. A.Both Statement I and Statement II are true
2. B.Statement I is true but Statement II is false
3. C.Both Statement I and Statement II are false
4. D.Statement I is false but Statement II is true