The Primary Difference Between Call by Reference Using Ref Versus

Multiple Choice

The primary difference between call by reference using ref versus out is ____.

A) ​ref requires the original argument be initialized, out doesn't
B) ​out can only be used with integral memory types, ref can be used with any type
C) ​ref requires the keyword ref be included in the call and heading, out doesn't
D) ​ref is pass by reference