## Questions 2-3
A thermodynamic system is taken from an initial state X along the path XYZX as shown in the PV-diagram.
2. For the process `X→Y,ΔU` is greater than zero and
(A) `Q<0` and `W=0`
(B) `Q<0` and `W>0`
(C) `Q>0` and `W<0`
(D) `Q>0` and `W>0`