When asking a question, people often change their at the end.
a. facial expression
b. gestures
c. pitch
d. volume

c. pitch

Explanation:

In English, as well as in most languages, people tend to change their pitch at the end of a question in order to make it clear that the speaker is looking for an answer. If we were to pronounce the question without this change in pitch, it is likely that people would mistake it for a statement. When writing, as this change in pitch is not possible, questions are usually identified by a question mark.

b

explanation:

sorry answered wrong answer