The correct option is C isthmus
Females have two fallopian tubes that extend laterally from the uterus. Each fallopian tube consists of three regions: infundibulum, ampulla and isthmus.
The funnel shaped portion of each fallopian tube which is close to the ovary is called infundibulum.
Infundibulum leads into ampulla which is the wider part of the fallopian tube.
Ampulla leads into isthmus of the fallopian tube which is a narrow, thick walled portion that joins the uterus.
Hence the part of the fallopian tube closest to the uterus is isthmus.
The lower cylindrical portion of the uterus which opens into the vagina is known as the cervix.