VBA code to sort a dataset with multiple columns based on a variable number of rows

Hi everyone,

I'm trying to build a macro that will automatically sort a full selection dataset upon opening the workbook in Excel. I'm having trouble defining the range because the number of rows within the dataset would vary depending on the file (but would all start in the same format, i.e., one file could have rows 5-10, another could have rows 5-25, but no spaces in between the data).

Input:
Cell A5 -> B5 -> C5
Category. A. B.
Category A 1% 90%
Category B 2% 70%
Category C 3% 80%
Category D 4% 55%

Desired output (sort "B." by ascending):
Cell A5 -> B5 -> C5
Category. A. B.
Category D 4% 55%
Category B 2% 70%
Category C 3% 80%
Category A 1% 90%

Any help would be appreciated!

Sorry, first time poster. I've attached a screenshot of the input... the selection always starts at A5 (row 5 is for headers) and has those 4 specific columns... it would be re-sorting the whole dataset by "positive" based on ascending order (where it's currently set up on descending order).

Screen Shot 2019-03-18 at 1.55.24 PM.png

This should work - thanks for the direction!