The correct answer to the Supporting Dancer quiz is False (the individual being lifted is not considered the Supporting Dancer). Think of Supporting Dancers as the equivalent of bases in cheerleading. In this example the Supporting Dancers are the individuals in contact with the performance surface supporting the Executing Dancer. From the Rules Glossary:
Executing Dancer: A dancer who performs a skill as a part of Groups or Pairs who use(s) support from another dancer(s)
Supporting Dancer: A dancer who performs a skill as a part of “Groups or Pairs” who supports or maintains contact with an Executing Dancer.
The explanation is based on the 2017-18 version of the dance rules dated August 30, 2017.