Assuming the |Rectangle| class is already designed with a constructor |__init__(self, x, y, width, height)|, which code snippet creates a square in the middle of a frame with FRAME_WIDTH = 400, FRAME_HEIGHT = 600?
1. square = Rectangle(FRAME_WIDTH/2, FRAME_HEIGHT/2, 100, 100)
2. square = Rectangle(FRAME_WIDTH, FRAME_HEIGHT, 100, 100)
3. square = Rectangle(FRAME_WIDTH-50, FRAME_HEIGHT - 50, 100, 100)
4. square = Rectangle(FRAME_WIDTH/2 - 50, FRAME_HEIGHT/2 - 50, 100, 100)
