Which of the Following Is an Effective Sentence Definition

Which of the following is an effective sentence definition?

A) Cardiovascular exercise equipment is used by people to exercise their cardiovascular system.
B) A canteen is a clear Nalgene bottle used to hold liquids such as water, lemonade, soda, and sometimes hot beverages.
C) Velo binding is when two plastic strips are placed on either side of the document and bound together with heat.
D) Thermography is a printing process in which a special powder is added to the wet ink on the surface of the paper and then heated.