Sign bit is $1 \implies$ number is negative
Exponent bits- $10000011$
Exponent is added with $127$ bias in IEEE single precision format. So, actual exponent $= 10000011 - 127 = 131 - 127 = 4$
Mantissa bits- $101000000000000000000000$
In IEEE format, an implied $1$ is before mantissa, and hence the actual number is:
$-1.101 \times 2^{4}$
$=-(11010)_{2} = - 26$
http://steve.hollasch.net/cgindex/coding/ieeefloat.html
Correct Answer: $C$