L3 slide 7: Which process is closest to reversible (ENGR5003)

L3 slide 7: Which process is closest to reversibleFrom lectureCurrent specThird1 marks2 min

ENGR5003 Lecture 3, slide 7 (Reasons for irreversibility)

Which of the following processes is closest to a reversible process?

AFree expansion of a gas into a vacuumBHeat transfer across a large temperature differenceCFrictionless compression carried out through a series of infinitesimally small pressure differencesDMixing of two different gases