Some desks are stools (I) + All stools are tables (A) ⟹ Some desks are table (I) ⟹ [Probable conclusion] ⟹ All desks may be tables (A). No chair is a desk (E) + Some desks are stools (I) ⟹ Some stools are not chairs (O*). Some tables are chairs (I) ⟹ [Probable conclusion] ⟹ Some tables may not be chairs (O). By elimination method - By 1, All desk can’t be table. Hence it is eliminated. By 2, No + some = some stool are not chair can’t be drawn. Hence it is eliminated. By 3, no table is chair. So possibility case can’t be drawn between them. Hence it is eliminated. Hence answer is option 4.