The correct option is D ≥ 45˚
Consider any triangle ABC, AM is a line connecting A to mid point of BC. Drop a perpendicular from A to BC touching BC at D. The angle ADM is a right-angled triangle with 45∘ – 45∘ – 90∘ . Hence DAM = 45∘ and BAM > 45∘ . BAM= 45∘ if ∠ABC =90∘. Hence, answer is option (d).