As shown in the picture, Xiao Ming saw the word "turn off the lights" when he observed the propaganda slogan "Please turn off the lights at hand" with optical instruments, so he can judge his use.

As can be seen from the figure, the word "turn off the light" is seen as an inverted and enlarged image, so the lens is convex, and the slogan is between more than one focal length and less than two focal lengths, so A, B and C are wrong and D is correct.

D is chosen.