Which of the following is generally accepted regarding the use of animals in research under Canadian ethical guidelines

A)  Animals can be used in research laboratories, but only in observational studies, not experimental studies. 
B)  Animals can be used for any form of research, regardless of the dangers associated with that research. 
C)  Animals are used in research only when there is a strong expectation that the results will benefit both humans and animals. 
D)  Animals can be used in research but can be harmed only when there is clear evidence that the results will lead to treatments or cures for existing human or animal disorders.