Match/Vlookup/Error-type Formula Needed

Hello,

I'm working on adding a failsafe for a sheet that multiple people will work with. I want an ERROR message to pop up if specific values don't match. The values that will be analyzed are based on two other data values matching. I can't get the table to format correctly, but column A is fruit, column B is country, and column C is a percentage.

For example:
Column A Column B Column C
Banana Europe 5%
Orange South America 5%
Banana Europe 10%
Orange Europe 5%

Row 1 and 3 have the same values for Column A and Column B, but different values for column C. Therefore, I want the formula to result in 5% (if the column A, B, and C values all match) but result in ERROR if Column C does not match (assuming column A and B do match).

Thanks for any help you can offer!