Carcass,

b can take any value from 31 to 39 because it is not given whether b is greater than 36, less than 36 or equal to 36.
Ranges can be 31-2 =29, 32-2=30, 33-2=31, 34-2=32, 35-2=33, 36-2=34, 37-2=35, 38-2=36, 39-2=37.
So, B C D E can be answer choices.
Kindly, suggest !!!

The range is the upper most value on one extreme and the lowest value on the other extreme.

B can take a value from 31 to 39 But we need the range that COULD be the value for b

Putting our value in increasing order we do have

2-3-5-15-17-19-22-36 AND we do know that b could be 31-32-33-34-35-36-37-38-39

Therefore b can take as values 36-37-38-39. Below 36 we will not have a range with b. So we have to put b on the other extreme to find the possible value

39-2=37 but is NOT among the choices
38-2=36 yes we do have
37-2=35 but is NOT among the choices
36-2=34 yes we do have

The only viable options are 38 and 36

D and E