This is a percent difference problem.
The formula for percent difference is ("new" - "base")/"base" = p/100 = p%
or you could say ("new" - "old")/"old" = p/100 = p%
Which number is the "new" number and which number is the "base" number? The base number is the amount that comes after the word "than" in the question.
State D comes after the word "than", so State D is the base.
The "new" number is State A and the base is State D.
(A - D)/D = p/100 = p%
(181 - 79)/79 = p/100 = p%
The question includes the word "approximately," so we can do a little bit of rounding. We'll say
(180 - 80)/80 = 100/80 = p/100 = p%
p = 125, therefore the answer is 125%
Answer D
Note, by the way, that since 100 in bigger than 80 the correct answer has to be greater than 100%.