Lock horns

Correct — B, argue about something. To lock horns with someone is to get into a direct dispute or confrontation with them. The picture behind the phrase is two horned animals such as bulls or stags pushing head to head with their horns jammed together.

Why the others are wrong

• (a)
  Be like a bull — This describes the animal rather than the meaning; the idiom is about the clash, not about resembling a bull.
• (c)
  Agree with someone — The reverse of the sense — locking horns is a fight, and agreement is 'seeing eye to eye'.
• (d)
  Think about the horns — A word-by-word reading of the phrase; an idiom carries a settled meaning that its separate words do not give.

'Lock horns' means to enter open conflict or argument with someone, usually over a particular issue.

Key facts

• The usual pattern is 'lock horns with someone over something'.
• 'Cross swords' is a close synonym.
• 'See eye to eye' is the opposite — to agree.

Common traps

• Choosing the literal option about bulls or horns.
• Picking the opposite sense, 'agree'.

No directly related past PYQ was found.

• practice — not a real PYQ

  'To cross swords with someone' means:

  • (a)to fight a duel for sport
  • (b)to quarrel or argue with them
  • (c)to travel together
  • (d)to make peace with them
  Answer(b) to quarrel or argue with them — the phrase means to come into open dispute.
• practice — not a real PYQ

  'To see eye to eye' means:

  • (a)to stare at someone
  • (b)to be in agreement
  • (c)to be suspicious
  • (d)to meet by chance
  Answer(b) to be in agreement — the phrase describes two people holding the same view.