Spot the odd one out from the following structures with reference to the male reproductive system:
1. Rete testis
2. Epididymis
3. Vasa efferentia
4. Isthmus
(d) Isthmus is the part of female reproductive system. The Fallopian tube (oviduct) in female reproductive system shows four regions, /.e.. infundibulum, ampulla, isthmus and uterine part. Isthmus has a narrow lumen and it joins the uterus. It is the line that demacrates the body of the uterus from the cervix.