1.Subconscious is the best synonym for subliminal- Option C is correct.

Subconscious is defined as:of or concerning the part of the mind of which one is not fully aware but which influences one’s actions and feelings.

Somo synonyms are: unconscious, latent, suppressed, repressed, subliminal, unfulfilled, dormant, hidden, concealed, underlying, innermost, deep, intuitive, instinctive, innate, involuntary;

2-The sentence that uses commas correctly is option B. The travelers saw pterodactyls, bats, and a Tyrannosaurus rex.

It is correct to place a comma before and in a list with more than ttwo elements listed.