i) Let p in R be a prime of a PID R. If A ad B are submodules of R/(p^n), n >=1 .

Show that either A belongs to B or B belongs to A. Deduce that R/(p^n) is an indecomposable R-module.

(ii) Let R be a PID and d is non_zero, non_unit. If R/(d) is indecomposable, show that d~p^n for some prime p in R.

Can you give me some hints how to do this question please?

Thank you so much