Final answer:
A Section cannot be dragged into a Landing Page because it represents a larger structural part that encompasses other elements, unlike draggable elements like Custom HTML, rectangles, and rich text.
Step-by-step explanation:
The element that CANNOT be dragged into a Landing Page is a Section. In most website builders or landing page creators, elements such as Custom HTML, rectangles, and rich text are designed to be individually dragged and dropped onto the landing page. However, a Section typically represents a larger structural part of a page that might contain other elements and is not usually draggable as a singular element like the others mentioned.