Which of the following words is closest in meaning to “Nodule”?

Nodule means a small lump.

• Correct answer - a lump: it has the same meaning as Nodule.
• scheme: a plan, often secret - wrong, it does not mean the same as Nodule.
• part of a computer: a piece of computer hardware - wrong, it does not mean the same as Nodule.
• unit: a single part or quantity - wrong, it does not mean the same as Nodule.