Read the given statements and conclusions carefully. Assuming that the information given in the statements is true, even if it appears to be at variance with commonly known facts, decide which of the given conclusions logically follow(s) from the statements.

Statement :

All roads are purple

Some purple are rock

All rock are doors

Conclusion :

I - Some roads are doors

II - Some doors are purple

III - Some roads are not doors

IV - All doors are rock

Either I or III and II follow