The numerical value of 5 se c^2 + 21 + co t^2 + 3 ^2 is?

Answer: Option A

$$\begin{array}{rl}& \frac{5}{\text{se}{\text{c}}^2\theta }\text{ + }\frac{2}{1+\text{co}{\text{t}}^2\theta }\text{ + 3}{\sin }^2\theta \\ & =5{\cos }^2\theta +\frac{2}{\text{cose}{\text{c}}^2\theta }+3{\sin }^2\theta \\ & =5\text{co}{\text{s}}^2\theta +2{\sin }^2\theta +3{\sin }^2\theta \\ & =5\left(\text{co}{\text{s}}^2\theta +{\sin }^2\theta \right)\\ & \left(\because {\sin }^2\theta +\text{co}{\text{s}}^2\theta =1\right)\\ & =5\times 1\\ & =5\end{array}$$