(c) Lower part of capsule
Explanation: The sporophyte of moss is differentiated into three parts foot, seta, and capsule. The capsule, in turn, is differentiated into 3 regions.
i. Apophysis - the sterile basal portion of the capsule, it is in continuity with seta
ii. Theca or body of capsule, which is the fertile region, and
iii. Operculum the apical region of capsule.
Apophysis is rich in chloroplast and thus the photosynthetic region of moss, it also provides nutrition to the developing sporangium.