All of the Following Are Proper Guidelines for Using a Microscope

All of the following are proper guidelines for using a microscope EXCEPT which statement?

A) Use one hand to carry the microscope.
B) Use only cleaning solution provided by your laboratory instructor to clean the microscope lenses.
C) Use only special lens paper to clean the lenses of the microscope.
D) Unplug the microscope by pulling on the plug, not by tugging on the electrical cord.