C. Why should we regard array-type function parameters as pointers to the first element of the array?

Simply put, it is two words, efficiency.

As we all know, in C function calls, parameters are passed by value, which means that a copy is generated for the real parameter during function calls, and then the function operates on this copy, that is, the function call that everyone knows will not modify the value of the real parameter, because the value is passed here.

Because function parameters need to be copied, if this function parameter is an array, this overhead may be significantly affected by performance. In general, this copy is useless, so for efficiency consideration, function parameters of the array type are considered as pointers to the first element of the array.

Of course, it can also be said that for performance considerations, it is a bit cool.