How can you prevent buffer overflow in C?

Preventing buffer overflow is crucial in C programming, and ensuring proper bounds checking is a highly effective method. Bounds checking involves verifying that any data written to a buffer remains within the allocated memory limits of that buffer. This means confirming that your code doesn't attempt to write beyond the size of the buffer, a common source of buffer overflows. By implementing bounds checking on array indices and ensuring that the data being copied or processed fits within the allocated space, you can significantly reduce the risk of overflow attacks that could lead to program crashes or security vulnerabilities.

Dynamic memory allocation is useful for managing memory at runtime, but it doesn't inherently prevent buffer overflows unless combined with bounds checking. While limiting the size of variables can also be a helpful practice, it does not address situations where a buffer could still be exceeded during operations like string manipulation. Relying exclusively on global variables can create additional potential issues, such as increased complexity and difficulties in tracking memory usage, which can also lead to errors and security risks. Hence, proper bounds checking is the most direct and effective method among the options to prevent buffer overflow.