Quadcopters are optimal configurations in the sense that they can navigate in the 3D space easily and yet are much less

[answerhappygod]

Quadcopters are optimal configurations in the sense that they
can navigate in the 3D space easily and yet are much less complex
compared to helicopters which have similar maneuvering ability.
However, this comes at a cost. The motion of a typical quadcopter
is constrained (see Q1). In this question you asked to advise an
alternative VTOL Micro Aerial Vehicle (MAV) design motion of which
is not constrained. Provide simple (hand) drawings of the proposed
design and explain its abilities. (Hint : You can benefit from
existing studies such as those listed in this paper.)