The three successive terms of a G.P. will form the side of a triangle if the common ratio r lies in
a. \(\left(\frac{\sqrt5-1}2,\frac{\sqrt5+1}2\right)\)
b. \(\left(\frac{-1\sqrt5}2,\infty\right)\)
c. \(\left(-\infty, \frac{\sqrt5-1}2\right)\)
d. none of these
