The word "intransigent'' means unwilling to change one’s views or agree — firmly uncompromising.
Step 1: Analyze the options:
- "Flexible'': Opposite of intransigent — open to change.
- "Transparent'': Means open or clear — not related.
- "Stubborn'': Unwilling to change opinion — directly matches "intransigent''.
- "Unpleasant'': Means disagreeable — unrelated to firmness of belief.
So, "stubborn'' is the best synonym for "intransigent".