I don’t think anyone knows this one not even James
None of those describe this function.
It's not a constant function, because it is not equal to a constant (something that isn't a variable)
It doesn't show direct variation, because it can't be represented in the form
y = kx.
It isn't an absolute value function because the absolute value isn't taken anywhere.
If it was an absolute value function it would look something like this:

It isn't a greatest integer function, because the greatest integer isn't taken anywhere.
If it was a greatest integer function it would look something like this:

Are you sure you typed that question right?
The only thing you can do with this expression is to factor a 5 out of the two terms: we have

Solution
The range is defined as:
Range = Max - Min
For this case we can conclude that the best solution would be:
B, C