Hello!
Option C is punctuated correctly.
The answer is not A, because the sentence contains no punctuation, therefore making it a run-on.
The answer also is not B, because a comma does not connect the sentence. The sections "Customer service must be a priority of all employees" and "ignoring our customer needs will surely put us out of business" are independent thoughts that cannot be connected only with a comma.
C is the correct answer because a semicolon connects two independent thoughts and shows how they are related without making the second section seem irrelevant.
I hope this helps you! Have a lovely day!
- Mal
