What mobile-device restriction applies to a Massachusetts driver under 18?

Correct answer: The driver may not use a mobile device except to report an emergency.

Why

A driver under 18 may not use a mobile telephone or covered electronic device while operating. The law provides a limited emergency defense; it does not permit ordinary calls merely because they are hands-free or because traffic has stopped. For this rule, a stationary vehicle outside the portion of the public way intended for motor-vehicle or bicycle travel is not operating. Stop only in a safe lawful place if device use is needed.

Verified against Massachusetts Driver’s Manual · Junior operator mobile devices · p. 48