In ΔABC, ∠B = 90° and AB : BC = 2 : 1, then value of (sinA + cotC) = ?

Answer: Option B

$$\begin{array}{rl}& \text{AC}=\sqrt{2^2+1^2}=\sqrt{5}\\ & \text{sin A}+\mathrm{cotC}\\ & \frac{\text{BC}}{\text{AC}}+\frac{\text{BC}}{\text{AB}}\\ & \frac{1}{\sqrt{5}}+\frac{1}{2}\\ & \Rightarrow \frac{2+\sqrt{5}}{2\sqrt{5}}\end{array}$$