Correct Answer & Explanation
Option A
• 'Falter' means to lose strength or momentum, hesitate, or move unsteadily.
• 'Waver' means to become unsteady, hesitate, or falter, making it the correct synonym.
• Options B, C, and D are incorrect as 'Stabilize', 'Persist', and 'Advance' imply remaining steady, continuing steadfastly, or moving forward.