The graph shown in Fig. represents the I-V characteristics of a zener diode. Which part of the characteristics curve is most relevent for its operation as a voltage regular?
A. `A,R` are true and `R` explains `A` correctly
B. `A,R` are true and `R` do not explain `A` correctly
C. `A` is true, but `R` is false
D. `R` is true, but `A` is false
