In a Δ ABC, the sides AB and AC are produced to P and Q respectively. The bisectors of ∠ OBC and ∠ QCB intersect at a point O. Then ∠ BOC is equal to:

• 90 ° + 1 ∠A 2
• 90 ° - 1 ∠A 2
• 120° + 1 ∠A 2
• 120° - 1 ∠A 2