The word "communication" is derived from the Latin word "communis," which means "common" or "shared." Communication involves sharing information between individuals or groups, which aligns with the meaning of "communis."
Step 1: Analyze the options.
(A) Communist: The word "communist" is unrelated to the root of "communication."
(B) Communis: This is the correct answer. The word "communication" comes from the Latin word "communis," meaning common or shared.
(C) Communication: This is the modern word, but it is not the root from which the term is derived.
(D) Command: Command is unrelated to the derivation of the word "communication."
Step 2: Conclusion.
The correct answer is (B), as "communication" comes from the Latin word "communis."
Final Answer:
\[
\boxed{(B) \, \text{Communis}}
\]