What happens if you access an array element in C whose subscript exceeds the size of the array?

Accessing an array element in C with a subscript that exceeds the bounds of the array results in undefined behavior. This means that the program tries to access memory that it is not supposed to, which can lead to various outcomes, including the potential for a program crash. When the subscript exceeds the allocated size of the array, you may inadvertently retrieve a value from memory that is not intended for the array, which can cause unexpected behavior or system instability.

This is a critical aspect of C programming because the language does not perform bounds checking on arrays. Hence, if you go beyond the defined limits of an array, you could be accessing memory that may belong to another variable or be unallocated altogether.

In contrast, the other options suggest behaviors that do not occur in C. The element is not automatically set to 0, nor does the compiler provide whether there’s an error at compile time for exceeding bounds; it treats access based on how the memory is laid out at runtime. The array also does not automatically grow in size; array size in C is static once defined, and attempting to access beyond its allocated size does not result in dynamically resizing the array.