The correct option is
C A- Peristomium, B-Mouth, C-Anterior, D- Clitellum, E-Segment, F-Anus, G-Posterior
Mouth: it is the terminal opening present in the first body segment of earthworm.
Peristomium: the first body segment of the earthworms is called peristomium.
Anterior: part of the body that lies towards mouth.
Posterior: part of the body that lies towards anus.
Segment: the body of earthworm is divided into various segments. There are around 100- 150 segments in an earthworm.
Clitellum: segment 14 to 16 in earthworm possess a thick band called clitellum. It has glands that secrete mucus and albumin. It helps in the formation of cocoon.