Which of the following loops is infinite (runs forever)?

		int a=1, b; do { b = a; } while(a<=10);
		i int a=1, b; while (a<=10) { a++; b = a; }
		int a=1, b; while (a<=10) { b = a; a++; }
		int a=1, b; do { a++; b = a; } while(a<=10);