OEThe structure of the sentence indicates that the blank opposes the word
“proven”; it should be something like unproven or not necessarily proven. The correct answers,
“putative” (generally thought to be) and
“conjectural” (hypothetical, speculative) both match this meaning.
“Corroborated” and
“irrefutable” are an incorrect pair of words that have meanings similar to
“proven.” “Incorrect” could also be seen as an opposite of
“proven,” but it does not have a match (and note that an unproven theory is not necessarily wrong).
“Irreconcilable,” which means incompatible or conflicting, also cannot be correct because it neither has a match nor fits the intended meaning
Answer: B,C