Answer:
B) Interaction
Step-by-step explanation:
While learning a language it is necessary to read, speak and listen to the language. The three aspects of language which utilizes the sense organs must be used.
A language can be read but in order to speak it two way communication needs to take place. While speaking real life situations makes it easier to learn. Pronunciations can also be made better by speaking.
Hence, interaction is required in both online and classroom-based environments.