Analysis (it's what I do)
Spell check is challenging the word "illusive" as possibly misspelled, so let's define these words:
illusive ~ adj. (literary) ~ deceptive; illusory; misleading; unreal.Elementary, my dear Watson! The maker of the quiz quite likely used the wrong word. Indeed, she or he should have referred to "life's most elusive questions." Analysis complete.
elusive ~ adj. ~ eluding clear perception or complete mental grasp; hard to express or define; puzzling, baffling.
If you want to take the same quiz, click here. Maybe it will also tell you what you already know.
By the way, can you name the "professor" in that photo above? That's Professor Minerva McGonagall of Hogwarts.