fgets() is the safe way to read strings including spaces. scanf("%s") stops at whitespace, gets() is deprecated and unsafe due to buffer overflow risks.

A static variable inside a function is initialized only once and retains its value between successive function calls. It has memory allocated in the data segment, not the stack.

Both are valid syntax. Option A declares an anonymous structure with immediate variable instantiation. Option B declares a named structure type that can be used later to create variables.

The volatile keyword tells the compiler that a variable's value may change unexpectedly (e.g., due to hardware, interrupts, or other threads), preventing compiler optimizations that assume the value doesn't change.

When ptr points to the array arr, ptr[1] is equivalent to *(ptr+1), which accesses the second element of the array, which is 2.

The increment (++) and decrement (--) operators have the highest precedence among all operators in C, followed by unary operators, then multiplicative, additive, and so on.

The 'break' statement is used to exit or terminate a loop or switch statement immediately. It transfers control to the statement following the loop or switch.

The while loop starts with i=0. It prints 0, then increments i to 1, prints 1, increments to 2, prints 2, increments to 3, and the condition i<3 becomes false, so the loop terminates. Output: 0 1 2

The free() function is used to deallocate memory that was previously allocated using malloc(), calloc(), or realloc(). This prevents memory leaks.