From the choices provided, choose the option that best expresses the meaning of the given idiom.
To pay back in the same coin.

Correct Answer: To get revenge for a past injury or treat someone as they treated you

Understanding the Idiom:
The idiom "to pay back in the same coin" means to retaliate against someone by treating them in the exact same manner as they treated you, typically in response to harmful, unkind, or unfair behavior. It is synonymous with expressions like "tit for tat" or "giving someone a taste of their own medicine."

Detailed Explanation of Options:
• To get revenge for a past injury or treat someone as they treated you: This correctly conveys the figurative meaning of retaliating or responding in equal measure to how one was treated.
• To exchange foreign currency for local money: This is an incorrect literal interpretation focused on monetary exchange.
• To settle an outstanding debt using exact currency: This takes the word "coin" literally to refer to paying back actual money, which is incorrect in an idiomatic context.
• To divide the profits from a joint investment evenly: This relates to financial business arrangements and has no connection to the idiom's meaning.

Therefore, the choice that best expresses the meaning of the given idiom is To get revenge for a past injury or treat someone as they treated you.