Are you required to trace back information on a subject to first publication for a citation on it? If there is a tree of papers on or involving X, all of which give a brief introduction to X and I need a citation for my use of X, do I need to give the root of the tree as a citation of X or can I cite any of the nodes in the tree that explain X for my use of it?

Concretely I need to cite why using point wise mutual information can be used to improve co-occurence matrix based word embeddings. I do not really know where PPMI was first used for this purpose, but I have stepped down towards the root for a few papers now. Do I need to find the paper that first used PPMI for this or can I cite any of the ones I already found?
I (as a mathematician) would use one of three options:


cite the most recent paper. This is what I do when I only need a reference to the topic and no particular result in detail; ideally, the most recent paper is a survey (or sometimes I pick the most recent survey), this way I can skip a lot of references in my own article saying, "see [xyz], and the references therein." This somehow implies that the contribution of my paper is related, but it is nowhere necessary to know the exact details of the results of that source.
cite the original source. This is rare in my case, because over the years people have added so much knowledge that citing the original works seems to be a bit out of date. I only do this when I really want to stress that this origin is important for my work in particular. As I said, this rarely happens. I am pretty sure that many people who cite the original source have never read the original source and just cite it "because you cite it."
cite some other paper(s) "from the tree" (as you call it). This is what I usually need and do, mainly because I need to refer to several different details from different sources. Then I have a reason for referring to an "inner node in the reference tree" (neither root nor leave), and I would only do that if I can give a reason, either only to myself, or even write in my own paper why I pick this particular reference.