Correct answer: (-∞, -√3) ∪ (√3, ∞) {-2, 2}
The correct option identifies the slopes of the line formed by points P and Q that create right angles with the line segment AB. The conditions for the angles being π/2 lead to restrictions on the slope m, specifically excluding values between -√3 and √3, as well as the slopes -2 and 2, which correspond to the perpendicularity condition.