Nothing is mentioned about positions of the fields.
Assuming fields to be in Sign, Exponent, Mantissa order.
Sign =0.
0.375= 0.25+0.125 which in binary base is 0.011. But we can't simply write 011 in mantissa as it is normalized form, need to consider implicit 1 also.
If we consider exponent as 001 (1 in decimal) and mantissa as 100 (4 in decimal) we will get number as:
+ 1.100 * 2(1-3) = +1.100 * 2(-2) = +0.011 (0.375 in decimal) this is what we were looking for.
Hence all the fields will be 0 001 100. B matches.