ABC analysis is based upon the principle that

Question $2$ options:

all items in inventory must be monitored very closely.

an item is critical if its usage is high.

more time should be spent on class $"$C$"$ items because there are more of them.

as with grade distributions in many MBA courses, there should be more medium$-$level $"$B$"$ items than either $"$A$"$ or $"$C$"$ items.

there are usually a few critical items, and many items which are less critical.