In this above question 

We use factorisation method and solve

$\begin{array}{l}\Rightarrow \text{? = 1225 = 5}\times \text{5}\times \text{7}\times \text{7}\\ \\ \Rightarrow \text{ ? =}\sqrt{\text{1225}}\text{ = }\sqrt{\text{5}\times \text{5}\times \text{7}\times \text{7}}\\ \\ \Rightarrow \text{ ? = 5}\times \text{7 \hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}(}\because \text{in square root, to}\\ \text{\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}remove root, we take pairs of two]}\\ \\ \Rightarrow ?\text{=5}\times \text{7=35}\end{array}$

Hence, Option E is correct.