Logical Deduction Q34

34.	Statements: All benches are desks. Some desks are roads. All roads are pillars. Conclusions:        I.            Some pillars are benches.     II.            Some pillars are desks.  III.            Some roads are benches.  IV.            No pillar is bench.
	A. None follows B. Only either I or IV, and III follow C. Only either I or IV follows D. Only either I or IV, and II follow E. All follow

Answer: Option D

Explanation:

All benches are desks. Some desks are roads.

Since the middle term 'desks' is not distributed even once in the premises, no definite conclusion follows.

Some desks are roads. All roads are pillars.

Since one premise is particular, the conclusion must be particular and should not contain the middle term. So, it follows that 'Some desks are pillars'. II is the converse of this conclusion and so it holds.

All benches are desks. Some desks are pillars.

Since the middle term 'desks' is not distributed even once in the premises, no definite conclusion follows. However, I and IV involve the extreme terms and form a complementary pair. So, either I or IV follows.