What is the correct syntax to define a method named CalculateAverage that calculates the average of an array of integers in C#?

A. CalculateAverage(numbers[]) { return numbers.Average(); }

B. double CalculateAverage(numbers[]) { return numbers.Average(); }

C. CalculateAverage(int[] numbers) { return numbers.Average(); }

D. double CalculateAverage(int[] numbers) { return numbers.Average(); }

Answer: Option D