Answer: The correct option is
(D) IV, II, III, I
Step-by-step explanation: We are given to organize the following expressions from greatest to least by number of terms :

We see that
number of terms in expression I is 1,
number of terms in expression II is 3,
number of terms in expression III is 2
and
number of terms in expression IV is 4.
Therefore, the descending order of the number of terms in the given expression is given by
4, 3, 2, 1
IV, II, III, I.
Thus, option (D) is CORRECT.