Answer: B
It is okay to use a UL approved extension cord on a TEMPORARY basis. You will, however, want to make sure that the extension cord can handle the load you are putting on it. Also, you are not allowed to modify the extension cord (don't remove the ground pin) or make a "home-made" extension cord.
Never tape or nail down an extension cord or run it under a rug. If the extension cord is placed where people will be walking, it must be covered by an approved protection bridge.
Interestingly, multi-outlet power bars with circuit breakers are not considered extension cords. These can be used on computers and other equipment on a permanent basis.
If you think you may be using an extension cord in the wrong way, we can help you get a proper outlet installed where you need it. Give us a call at (330) 762-3343 or email info@autotechfire.com.