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

Auxiliary means supplementary; accessory.

• Correct answer - accessory: it has the same meaning as Auxiliary.
• authentic: genuine - wrong, it does not mean the same as Auxiliary.
• chasteness: purity; modesty - wrong, it does not mean the same as Auxiliary.
• primary: first or main - wrong, it does not mean the same as Auxiliary.