$\begin{array}{l}\text{Here,}\\ \Rightarrow \frac{1}{2}\text{\hspace{0.17em}of\hspace{0.17em}3842+15\% of ? = 2449}\\ \\ \Rightarrow \frac{1}{2}\times 3842+\frac{15}{100}\times x=2449\\ \\ \Rightarrow \text{1921+}\frac{15}{100}\times x=2449 [\text{put ?}=x]\\ \\ \Rightarrow \frac{15x}{100}=2449-1921\\ \\ \Rightarrow \frac{15x}{100}=528\\ \\ \Rightarrow x=\frac{528\times 100}{15}\\ \\ \Rightarrow x=\frac{528\times 100}{15}=35.2\times 100=3520\end{array}$

Hence, Option A is correct.