Multiple choice

He proved that he was right and his critics had to back .......

  1. out

  2. up

  3. down

  4. for

  5. on

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

'Back down' is the correct phrasal verb meaning 'to withdraw a position' or 'to admit defeat'. The preposition 'down' indicates retreating from a previously stated position or argument.