Unlike a mere ______ who simply disputes facts, the true ______ questions the very foundations of knowledge and challenges the assumptions upon which an entire system of thought rests.
Correct: A
An iconoclast is someone who attacks or criticizes cherished beliefs, institutions, or traditions, often targeting the foundational principles themselves. A sceptic questions whether certain claims are true, but typically works within an existing framework. The sentence distinguishes between someone who disputes facts (sceptic) and someone who challenges foundational assumptions (iconoclast), making the correct pairing 'sceptic, iconoclast'.