Answer: (A) Classroom teaching and lectures.
Step-by-step explanation:
The classroom teaching and the lectures expertise is one of the form of communication in which by using the teaching expertise such as knowledge, voice and gesture we can easily communicate with the students in very efficient manner.
The classroom teaching expertise is one of the method in which the teachers are get proper training for handling the teaching task and they also developed their teaching skills.
Therefore, Option (A) is correct.