Which among the following is the commonest site of feilisation in uterine tubes?

The uterine tubes, or oviducts, or Fallopian tubes are two muscular tubes with considerable mobility, each measuring about 12 cm in length. Each has a funnel-shaped end, the infundibulum, opening into the peritoneal cavity next to the ovary and with a fringe of finger like extensions called fimbriae. The sequence of regions along each tube is as follows: Infundibulum, Ampulla, the longest and expanded area where feilization normally occurs, Isthmus, a more narrow region nearer the uterus, and Uterine or intramural pa, which passes through the wall of the uterus and opens into the interior of this organ. Ref: Mescher A.L. (2010). Chapter 22. The Female Reproductive System. In A.L. Mescher (Ed), Junqueira's Basic Histology: Text & Atlas, 12e.