National Geographic quiz

A hot topic that you'dve probably heard: On both NPR's All Things Considered and CNN, a story ran 'bout the National Geographic Geography quiz taken by groups of 18 to 24-year-olds from various countries. I'll leave the links to tell of the US group's horrid geographic illiteracy, and point out that the general public can also take a SAMPLE quiz and see whether they're a cartographical wunderkind like Sweden or as lost as an American or Mexican Gen Y-er.
Me? Only one wrong. Apparently Christianity is the world's most popular religion. I answered Islam. I'd hoped for Islam. In high school, I vaguely remember checking out some book on History's Hundred Most Influential People (or something like that), where it ranked 100 (or 500?) scientists and prophets and despots and Men-of-The-Years etc by how many people that they've influenced. The reader could then look through the index and see how well Einstein does against the Buddha or Ghandi vs. Churchill or if any US Presidents made the top 100 (or 500?, or a thousand? can't remember). anyway, what I confidently remembered is that Jesus came in third, trailing behind Isaac Newton and the most influential mind in all of human history (according to this book) - Muhammed!! A political as well as spiritual leader, founding a major religion under which great advances in learning, politics, and art spread throughout a huge area of the world in a relatively short period of time and whose innovations all modern thought and science hinges on.
Unfortunately, the above is only my vague memory of that forgotten author's assertion and is greatly distorted. There are more Christians than Muslims. As neither, I'm greatly disappointed.
A final thought on the National Geographic quiz - I'm noticing that the public online quiz is only a SAMPLE quiz, not the one that the 18 to 24 year old sample group took. I suspect that the online SAMPLE quiz is designed for us general public to freak out, say "those dumb American kids got THIS wrong!!", and immediately cough up a pledge to National Geographic to further their mission of Geographic Literacy (complete w/ snazzy colour photos of exotic pre-industrials to insulate our post-colonial fantasy worlds). My guess is that the kids had some tougher questions.