Explanation:

Let’s break this down:

- “A lame excuse” means an excuse that’s not convincing—it’s weak, and people can see right through it.

- Option 1: No excuse — That would mean nothing at all was given as an explanation. That’s not it.

- Option 2: Explanation — An explanation could be anything, strong or weak. Too general. Doesn’t fit the idiom.

- Option 3: Weak excuse — This nails it. “Lame” in this idiom means poor, feeble, not credible.

- Option 4: Strong excuse — That’s the exact opposite of what “lame excuse” means.