$\begin{align}0.085 \times 2 &= 0.17 \to 0 \\ 0.17 \times 2 &= 0.34 \to 0\\
0.34 \times 2 &= 0.68 \to 0 \\
0.68 \times 2 &= 1.36 \to 1\\
0.36 \times 2 &= 0.72 \to 0\\
0.72 \times 2 &= 1.44 \to 1\\
0.44 \times 2 &= 0.88 \to 0\\
0.88 \times 2 &= 1.76 \to 1\\
0.76 \times 2 &= 1.52 \to 1\end{align}$
So, $0.085_{10} = (0.000101011\dots)_2$
$=1.01011 \times 2^{-4}$ (normalized form)
In IEEE 754 representation, we skip the leading 1 and also the exponent has a bias of +127 for single precision. So, here the mantissa will be $0.01011\dots$ and exponent is $-4+127 = 123_{10} = (1111011)_2 = (01111011)_2$ (exponent is of 8 bits in IEEE 754 representation).
So, the only option matching is B.
Ref: http://steve.hollasch.net/cgindex/coding/ieeefloat.html