Answer:
The correct option is B) eight fewer than a number
Explanation:
Consider the provided expression

Let n is a number.
For negative sign we can use less than, fewer, decreased.
Now consider the provided options.
a number less than eight can be written as: 8-n
eight fewer than a number can be written as: n-8
eight decreased by a number can be written as: 8-n
a number subtracted from eight can be written as: 8-n
Thus, the correct option is B) eight fewer than a number