Return values from a pivot table column into a new column

Hi, this is probably a very simple question but I haven't come across this before.
I have a pivot table where my columns have three possible values: let's say B, C and D.
Each row has a possible value out of B, C or D and it's represented by a 1. So for example in row 13, I will have a 1 for column B and blank values for C and D.
I want to have a new column (column E) with a formula that displays the actual result (e.g. B) instead of the 1's

How would I do that?

Thanks so much!