count the number of prime numbers in an array

public static int solution(int[] A)
{
    int count = 0;
    for (int i = 0; i < A.Length; i++)
    {
        if (isPrime(A[i]))
        {
            count++;
        }
    }
    return count;
}

private static bool isPrime(int n)
{
    //check if n is a multiple of 2
    if (n % 2 == 0)
        return false;

    //if not, then just check the odds
    for (int i = 3; i * i <= n; i += 2)
    {
        if (n % i == 0)
            return false;
    }
    return true;
}