Correct Answer - Option 2 : 9

**Concept used :**

sin2 θ = 1 - cos2 θ

**Calculations :**

9 sin2 θ + 16 cos2 θ = 9 sin2 θ + 16 ( 1 - sin2 θ)

⇒ 9 sin2 θ + 16 - 16 sin2 θ

⇒ -7 sin^{2} θ + 16

⇒ -7 + 16 (for least value of the equation value of sin^{2} θ must be equal to 1)

⇒ 9

**∴ Option 2 will be the correct choice.**