Final answer:
To keep the navigation bar visible while scrolling, use the B) fixed type of positioning. Hence, B) is correct.
Step-by-step explanation:
If you want your navigation bar to remain visible, even when the user scrolls downward, you should use the fixed type of positioning.
This type of positioning allows the navigation bar to stay in a fixed position relative to the browser window, regardless of scrolling.
By applying the CSS property 'position: fixed' to the navigation bar element, it will remain at a specific location on the screen.