The pronoun “none” can be singular or plural depending on the meaning, but when referring to “not one” of the group, it is treated as singular.
Here, “None of us was comfortable” means “not one of us was comfortable,” making singular agreement correct.
Option (A) uses “were,” which implies a plural sense; however, the intended meaning is singular.
Option (C) and (D) are awkward because “none among us” or “none amongst us” is less common and unnecessarily formal in modern English, and they also incorrectly use “were” for a singular meaning.
Option (B) correctly pairs “none” (singular) with “was” (singular verb) and maintains the most natural expression.