I voted "less info" and I think the "fewer" changes the sentance and is incorrect.
the second answer must be wrong because it would need to be... "The less people WHO know about it..."
I am just an English learner but I guess it should be " less info " refer to the grammar rules. The word " less" cannot be used for a countable word. I wonder if I am correct. Is there any native speaker language teacher here?
Many native speakers use "less" for countable nouns. Purists dislike this, but it is a fact of life.