yes, it means nickel but it also means yellow. Don't mark it wrong.
In this skill they want you to learn about Money, which is why only "nickel" is accepted here.
Unfortunately when you choose to practice your weakest words, the word will show up without the skill context so you can't tell if it belongs to a color skill or a money skill.
Is there any context why yellow would also be the same word for a nickel?
money be GREEN