What does intonation specifically refer to in the context of speech?

Intonation refers specifically to the variations in pitch over the course of a phrase or sentence. It plays a crucial role in conveying meaning, emotional nuance, and syntactic structure in spoken language. By rising or falling in pitch, speakers can indicate different types of sentences, such as questions versus statements, or express excitement, uncertainty, or other emotions. This melodic aspect of speech is fundamental to communication, as it often helps listeners discern the underlying intent or mood beyond the actual words spoken. The use of pitch variations is a vital component of expressive speech, making option B the correct choice.