Noun

one who assumes responsibility for some other person or thing

https://www.merriam-webster.com/dictionary/sponsor

City Tech Library Instructions’

“who is the author/ publisher/source/sponsor?

I thought i knew what a sponsor was but I was confused by the way it was used in this sentence. I looked it up and realized a sponsor is not just someone who supports another individual but someone who takes responsibility too. Now I understand the context that sponsor was used in this sentence.