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 follows from the statements.

Statements:
All computers are laptops.
All hard disks are pen drives.
No pen drive is a keyboard.
No computer is a hard disk.

Conclusions:
I. Some pen drives are not laptops.
II. No keyboard is a computer.
III. No hard disk is a laptop.
IV. All pen drives are not keyboards.

Only conclusion IV follows