Final answer:
The word 'gesticulation' in the passage refers to a form of communication using expressive movements or gestures.
Step-by-step explanation:
The word 'gesticulation' refers to a form of communication that involves using expressive movements or gestures.
It is not related to utterance or phrase as they typically involve spoken or written words.
Similarly, it is not related to an oath, which is a solemn declaration or promise.
Therefore, the correct answer is B) Signal.