Two researchers independently code 40 transcript segments and agree on 34. Why is the resulting 85% agreement figure a weaker guarantee than it appears?

D. Because some agreement would occur by chance alone.

Raw agreement has a floor that has nothing to do with skill: two coders assigning at random over two categories agree about half the time, so 85% is 85 against a baseline of 50. Kappa asks how much of the room above chance was actually captured, which is why the same 85% can be excellent or mediocre depending on the coding scheme's structure.