Answer:
C. Webcam, speakers, and microphone is the correct answer.
Step-by-step explanation:
Letter A is incorrect because a scanner is hardly ever used in a video conference since the "Share Screen" option is usually available and documents can be sent through email.
Letter B is incorrect because a printer doesn't have any function in a video call.
Letter D is also incorrect because the projector is unnecessary since everything can be done in the screen.
Letter C is the correct answer because the webcam is necessary for the image; the speakers allow the audience to listen to the other part; the microphone is a must since it will give people the chance to interact with their voices and not only through the video.