How to Return Multiple Results as Comma Seperated Values

What formula(s) should I use instead of INDEX and MATCH to return multiple values? In the attached example, I would like Column B to list multiple results as a comma-separated list. Using row 2 as an example, I would like to see Product 1, Product 3, Product 5 as the returned results. 

The formula I used in the example below is:

=IFERROR(INDEX($C$1:$L$1,,MATCH("Yes",$C2:$L2,0)),"")

Thanks!