Select the sentence that uses the given idiom correctly.
A dime a dozen

Correct option is A

"A dime a dozen" means something is very common and of little value. Option (a) "Her ideas were worth a dime a dozen and didn't impress the boss" correctly uses this idiom, indicating that her ideas were unimpressive and not unique.

Explanation of other options:

• (b): Incorrect usage. The idiom implies something common, not rare, so tickets selling out quickly wouldn't fit.
• (c): Incorrect usage. If the desserts were special, they wouldn't be referred to as "a dime a dozen."
• (d): Incorrect usage. Rare finds are not common, so this sentence contradicts the meaning of the idiom.