Anew multicellular organism has been discovered, and scientists want to study the organism’s cell structures, including organelles. which microscope should they use? . a. scanning electron microscope. b. transmission electron microscope. c. compound light microscope. d. simple microscope

The microscope they should use is the transmission electron microscope. 
The transmission electron microscope is a type of microscope that has an electron gun, which produces the electron beam, and the condenser system, which focuses the beam onto the object, the image producing system , consisting of the objective lens, movable specimen stage, and intermediate and projector lenses; the image recording system, which converts the electron image into some form perceptible to the human eye. It is used to observe the features of very small specimens.