First Multiplication Iteration
Multiply $0.25$ by $2$
$\begin{array}{c c c}0.25 \ast 2 = 0.50\;\text{(Product)} & \text{Fractional part} = 0.50 & \text{Carry} = 0 \textbf{ (MSB)} \end{array}$
Second Multiplication Iteration
Multiply $0.50$ by $2$
$\begin{array}{c c c}0.50 \ast 2 = 1.00\;\text{(Product)} & \text{Fractional part} = 1.00 & \text{Carry} = 1 \textbf{ (LSB)} \end{array}$
The fractional part in the $2$nd iteration becomes zero and hence we stop the multiplication iteration.
Carry from the $1$st multiplication iteration becomes MSB and carry from $2$nd iteration becomes LSB.
So the result is $0.01$
Correct Answer: B.