Step-by-step explanation:
True. The MM (mouth morpheme) /clenched teeth/ is often used to convey frustration or anger in ASL. Mouth morphemes play an important role in ASL by adding additional meaning and nuances to signs. In this case, the /clenched teeth/ mouth morpheme can be used in combination with appropriate facial expressions, body language, and signs to convey frustration or anger. It adds emphasis and intensity to the overall expression and helps to convey the intended emotions more effectively.