Line CD is a straight line.
∠COD = 90°
Given that adjacent angles on a straight line add up to 180°,
∠BOD + ∠COD = 180°
∠BOD + 90 = 180
∠BOC = 90°
∠FOD = 90 - 15 - 12 = 63°
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Answer: ∠FOD = 63° (Answer C)
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