Which of the following statements correctly defines continuity at a point c?

A function is continuous at point c if the limit as x approaches c is greater than the function value at c.

A function is continuous at point c if the limit as x approaches c is less than the function value at c.

A function is continuous at point c if the limit as x approaches c does not exist.

A function is continuous at point c if the limit as x approaches c is equal to the function value at c.