Return the header of the table based on the data in array

Hello,

I have a huge true/false array with thousands of rows and 23 columns. Each row should only have one column displaying "True" and rest of the columns would be "false". I would like to add a column to detect if there's more than one "True" in that given row. If there's only one "True" in that row, I would like to add a second column to display the header of the column that has the "True".

I'm very bad at explaining this, but please look at the attached Excel sheet to get a better understanding. Thank you for your help in advance.

None of the rows contain more than one TRUE, so there are no errors to find ...

In L2 copied down:

=IF(COUNTIF(A2:K2,TRUE)>1,"Yes","")

In M2 copied down:

=INDEX($A$1:$K$1,MATCH(TRUE,A2:K2,0))