question: unblocked:congestion
choices.label: A B C D
choices.text: firm:loose detailed:brief steadfast:worry male:female
explanation: "unblocked" means unimpeded passage. "Congestion" is often used to describe vehicles. "firm" is not the opposite of "loose". "detailed" and "brief" have opposite meanings, and "detailed" and "brief" are juxtaposed. "steadfast" is not the opposite of "worry". "male" and "female" are antonyms, and "male" and "female" conflict.
relation: unblocked congestion R2.6
relation: detailed brief R2.6
relation: male female R2.5