Q. When Britain adopted the decimal system for its money, it changed . . . . . . . . relatively smoothly.
✅ Correct Answer: (C)
over
Explanation: 'Change over' means 'to stop using or having one thing and to start using or having something else'. Hence it makes the sentence meaningful.
Explanation by: Team MCQ Buddy
'Change over' means 'to stop using or having one thing and to start using or having something else'. Hence it makes the sentence meaningful.