The correct answer to the Simultaneous Tumbling quiz is False. Individual Rule 3 states:
Simultaneous tumbling over or under another dancer that includes hip-over-head rotation by both dancers is not allowed.
Only one of the dancers is performing a hip-over-head rotation skill which would mean this skill is Legal.
The explanation is based on the 2017-18 version of the dance rules dated August 30, 2017.