Concept:Use trigonometric identities to simplify denominators: csc2θ−cot2θ=1 and sec2θ−tan2θ=1.Explanation:Rewrite the given equation using the identities:11+11=2sinθSo 2=2sinθ.Divide both sides by 2: 1=sinθ.We know sinθ=1 when θ=90∘.Answer:θ=90∘ (Option D)