Concept:The Over-Head Projector (OHP) is designed specifically to project transparencies onto a screen or wall.
Explanation:Transparencies are clear sheets that display text, images, or diagrams when placed on the OHP.
The projector's light passes through the transparency, projecting the content onto a surface.
Still pictures must first be printed on transparencies to be used with an OHP.
Motion pictures require film or digital projectors, not OHPs.
PowerPoint presentations (PPT) are shown on digital projectors; to use them on an OHP, slides must be printed on transparencies.
Thus, the OHP is primarily meant for transparencies.
Answer:C. Transparencies