**Correct option ** (A) → (i); (B) → (iii); (C) → (ii); (D) → (ii)

**(A) ** sin^{2} (A) + sin^{2} (B) = sin (A + B)

**(B) ** bc/2cos A = b^{2} + c^{2} - 2bc cos A

Hence, the triangle is isosceles.

The triangle is equilateral.

**(D)** If a, b, c are in AP. and ha, h_{b}, h_{c} are in AP, where h_{a}, h_{b}, h_{c }are the altitudes, then a = b = c

The triangle is equilateral