what could be the range of a set consisting of odd multiples of 7?
The question may not be incorrect. You need to provide the options. The question says: What could be
... There are many numbers that could be the range of such a set but there would be only one option which could possibly be the range of a set of odd multiples of 7. There is a constraint on this range.
The odd multiples of 7 are 7, 21, 35, 49, -7, -21, - 35 etc etc
So a set consisting of only odd multiples of 7 will have a range which is an even number (Greatest Odd Number - Smallest Odd Number)
Also, the range will be a multiple of 7. Under these constraints, only one option will be correct.