Answer: Choice A
An inverse variation is of the form y = k/x which can be rearranged into x*y = k. The k refers to any fixed single number.
In the case of choice A, k = 105. This is because
x*y = 1*105 = 105 for column 1
x*y = 3*35 = 105 for column 2
x*y = 5*21 = 105 for column 3
x*y = 7*15 = 105 for column 4
Each product is 105, showing that x*y = 35 or y = 35/x is the equation that models the data.
The other tables have columns that multiply to values that aren't consistent with one another. Example: table 2 has column 1 multiply to 1; while column 2 multiplies out to 27. This is why these other choices are non-answers.