If e≠f and e·f≠0, which of the following may be true?
Choose the correct choice from the following answers:
A) e=f B) e.f=0 C) (e+f)(e-f)=0 D) e^2 = f^2 E) e^2+f^2 =0
except c all conditions are not as per question   (e+f)(e-f)=0
<result>C</result>
If e≠f and e·f≠0, which of the following may be true?