ratio of circumferential (hoop) stress to the longitudinal stress

Question

A thin cylindrical pressure vessel with closed-ends is subjected to internal pressure. The ratio of
circumferential (hoop) stress to the longitudinal stress is

(a) 0.25                     (b) 0.50
(c) 1.0                       (d) 2.0

Answer 1

i.e.., The ratio of
circumferential (hoop) stress to the longitudinal stress is 2