Statements: No man is sky. No sky is road. Some men are roads. Conclusions:  No road is man. No road is sky. Some skies are men All roads are men.

II is the converse of the second premise and so it holds.

No man is sky. No sky is road.

Since both the premises are negative, no definite conclusion follows.

No man is sky. Some men are roads.

Since one premise is particular and the other negative, the conclusion must be particular negative and should not contain the middle term. So, it follows that 'Some roads are not skies'.

No sky is road. Some men are roads.

As discussed above, it follows that 'Some men are not skies'.

Hence, only II follows.