$\dfrac{\text{sin A tan A}}{1 - \text{cos}^2 A}$ is equal to :

1. cos A

2. sec A

3. cosec A

4. sin A

Solving,

$\Rightarrow \dfrac{\text{sin A tan A}}{1 - \text{cos}^2 A} \\[1em] \Rightarrow \dfrac{\text{sin A tan A}}{\text{sin}^2 A} \\[1em] \Rightarrow \dfrac{\text{tan A}}{\text{sin A}} \\[1em] \Rightarrow \dfrac{\dfrac{\text{sin A}}{\text{cos A}}}{\text{sin A}} \\[1em] \Rightarrow \dfrac{\text{sin A}}{\text{sin A} \times \text{cos A}} \\[1em] \Rightarrow \dfrac{1}{\text{cos A}} \\[1em] \Rightarrow \text{sec A}.$

Hence, Option 2 is the correct option.