Factor out the cosθ: cosθ (2sinθ + sqrt3) = 0 Therefore, the only ways this can happen are if either cosθ = 0 or if (2sinθ + sqrt3) = 0 The first case, cosθ = 0 only at θ = pi/2, 3pi/2. The second case, (2sinθ + sqrt3) = 0 simplifies to: sinθ = (-sqrt3)/2 θ = 4pi/3, 5pi/3 Therefore the answer is A.