The correct answer is C. 400.
The code will first check if num is less than or equal to 100. Since 200 is less than or equal to 100, the code will execute the first statement, which sets num to num * 2. This will set num to 200 * 2 = 400. The code will then check if num is greater than 500. Since 200 is not greater than 500, the code will not execute the second statement. The code will then reach the end of the if-else statement and the value of num will be 400.
Option A is incorrect because the code will not execute the second statement, which sets num to num * 3.
Option B is incorrect because the value of num will be 400, not 200.
Option D is incorrect because the value of num will be 400, not 600.