Which design element used on a Web page demonstrates the closure principle?

Upon clicking the navigation tab at the top of the page, a list appears; the background for the list is blue, whereas the background color of the main Web page is white.

The logo includes an image of three blue circles with triangular white gaps positioned such that it looks like a triangle is overlapping the circles.

The same shape is applied to a group of objects that are part of a group.

The recommended steps to follow are aligned horizontally in a straight line.