If the tangent to the curve y = x + siny at a point (a, b) is parallel to the line joining $\left(0,{3\over2}\right)$ and $\left({1\over2},2\right)$, then

(1) |b – a| = 1

(2) $b={\pi\over2}+a$

(3) |a + b| = 1

(4) b = a

(1) |b – a| = 1

(2) $b={\pi\over2}+a$

(3) |a + b| = 1

(4) b = a