RandomNumberGenerator proper usage

I would like to generate a salt using a secure PRNG. I've read that the newest and recommended way to achieve this is to create a RandomNumberGenerator instance to GetBytes. However, I am not so sure which way should I follow:

// CODE 1

private static byte[] GenerateSaltNewInstance(int size)
{
    using (var generator = RandomNumberGenerator.Create())
    {
        var salt = new byte[size];
        generator.GetBytes(salt);
        return salt;
    }
}

// CODE 2

private static RandomNumberGenerator rng = RandomNumberGenerator.Create();

private static byte[] GenerateSaltStatic(int size)
{
    var salt = new byte[size];
    rng.GetBytes(salt);
    return salt;
}

What is the difference? Basically in the first version of this method I am creating a new instance of RandomNumberGenerator every time. In the second one I am using a static instance initialized once.

Which one should I choose? In articles I see people following the first path, but I don't feel why it would be a better idea to create RandomNumberGenerator 10000 times :P