B. inconsiderate, because a synonym is something that has a similar meaning to a word
Language is a system of signs represrnting ideas to convey a message. Those symbols, which are words can be arbitrary, ambiguous, abstract representations of other phenomena. Words are not intrinsically connected to what they represent. Meanings of words can shift over time. The arbitrary character allows us to invent new words.
Language is ruled guided, simply put, verbal communication is guided by unspoken but broadly understood rules.
So I would say that option A, C and D are correct.
Meanwhile, I think that option B is incorrect since a mean of communication is understood as the tool and technology employed in order to convey a message, exchange information, ideas.
The sentence "Moreover, it is probably just as valuable or more valuable to us now, than it was in the ancient past".
A sentence that includes an independent clause and at least one dependent clause is called a complex sentence.
