The following code will generate a compiler error.

string GetAgePhrase(int age) 
  if (age > 60) return "Senior";
  if (age > 40) return "Middle-aged";
  if (age > 20) return "Adult";
  if (age > 12) return "Teen-aged";
  if (age > 4) return "Toddler";

Which of the following statements, inserted as the last line of the 
function, would solve the problem?

A return needs to be done because the method expects a string to be returned