Inline functions tend to reduce binary size because they replace function calls with code directly inserted at the call site. This can lead to more efficient code and smaller binary sizes.

When a function finishes executing, the local variables defined inside it are automatically freed, and their memory is reclaimed. They do not persist after the function call.

Using a pointer to a structure allows direct access to its elements, enabling efficient manipulation and modification of the structure's data.

The correct option is b. It returns a NULL pointer. When the fopen() function fails to open the specified file, it returns a NULL pointer, indicating that the file opening was unsuccessful. Programmers can then check for this NULL value to handle errors gracefully.

When you define a structure in C, memory is allocated for the structure itself, which includes memory for all its members.

In a union, all members share the same memory location. Unions allow different variables to occupy the same memory space, providing efficient storage.

Using pointers to structures allows for more efficient memory allocation since only memory addresses are stored, reducing memory overhead. It also helps in preventing memory leaks by allowing explicit memory deallocation.

When using nested loops, it's important to consider the potential impact on performance. The number of iterations in nested loops can grow exponentially, especially if the outer loop iterates N times and the inner loop iterates M times, resulting in N * M iterations. This can lead to performance issues, so it's essential to carefully plan and optimize nested loop usage.

In C, arithmetic operators have the highest precedence, meaning they are evaluated first in an expression.

The primary difference between the scope and lifetime of a variable is that scope refers to where a variable can be accessed, while lifetime indicates how long the variable exists in memory.