Let 0 < α < π/2 be a fixed angle. If P = (cosθ, sinθ) and Q = cos(α – θ), sin(α – θ)Q obtained form P by
a. clockwise rotation around origin through an angle α
b. anti-clockwise rotation around origin through an angle α
c. reflection in the line through origin with slope tan α
d. reflection in the line through origin with slope tan α/2