How to search only items containing a whole phrase, without retrieving all items containing words that constitute the phrase?

want only items containing a whole phrase “option contract”
do not want items containing only separate “option” or “contract”

I also want this, as well as a “whole word” search (if the word is in double quotes), in order to find single words that happen to commonly appear as substrings of other words.

As a workaround, maybe try “word " or " word”? Does that work for your use case?

That works unless you are a searching for a single-word item that happens to also be a common substring of other words, e.g. searching for Mom will also find moment, momentum, cardamom, etc.