Or alternatively, the existence of (b) means that (a) is generally understood to mean "Linda is a bank teller, and is NOT active in the feminist movement", regardless of how literally the instructions say to take it.
Either way, it's more a failure of communication between the experimenters and the subjects, rather than a failure of rationality on the part of the subjects. Which is still interesting (and perhaps more interesting), but in a completely different way.
Is it? I didn't interpret it that way, and that isn't what the question says. And why would it be "understood" that is what is being asked? Logically, the answers would be "she is a feminist" and "she is not a feminist", there would be no reason to construct the answers with the information that she is a bank teller if that is what was being asked.
This seems like another detail that rational thinking picks up- if you stop and think about the answer format the "generally understood" interpretation doesn't make any sense.
The answers given don't make sense together, and don't fit the question. I am speculating that the usual way (for people who don't prefer interacting with machines to interacting with people, which would be most people) to read this is to assume someone was careless/sloppy, and to mentally "correct" the answers to the nearest thing that makes the most sense before answering.
Either way, it's more a failure of communication between the experimenters and the subjects, rather than a failure of rationality on the part of the subjects. Which is still interesting (and perhaps more interesting), but in a completely different way.