Answer:
sounds like all of the above
Explanation:
only one im not 100% sure on is to examine a question's reliablity
An overhead projector is required to display content on transparencies. A transparency is a thin sheet of plastic in which light is reflected upon to display content.The light source emits light towards the transparency and then the image is displayed on the wall. Usually, this light source comes from below and lights upward and so the content is depicted above or overhead.