“…Modelling after Iwasawa's ideas, Mazur developed an analogous approach towards studying the arithmetic of an abelian variety via examining the variations of its p-primary Selmer groups in a Z p -extension (see [34]). Recently, there have been great interest in the study of a certain subgroup of the p-primary Selmer group, called the fine Selmer group (for instances, see [6,18,28,30,31,32,45,48]). In the fundamental paper of Coates-Sujatha [6], they have examined this fine Selmer group in great depth and made several conjectures on its structure.…”