The decimal value 0.5 in IEEE single precision floating point representation has

In IEEE 754 single-precision format:

1. The binary representation of the decimal number $0.5$ is $(0.1)_2$.

2. Normalized scientific notation is:

   $$0.5 = 1.0_2 \times 2^{-1}$$

3. The actual exponent value is $-1$ (stored as a biased exponent $E = -1 + 127 = 126$).

4. The significand has an implicit leading $1$, so the stored fraction (mantissa) bits after the binary point are $000\dots000$.

Thus, the representation has fraction bits of $000\dots000$ and an exponent value of $-1$, which corresponds to option (B).