The correct option is
B a-cervix, b-uterine cavity, c-fallopian tube, d-ovary
The female reproductive tract contains ovaries, oviducts or fallopian tubes, uterus, cervix, and vagina. The ovaries are located on side of lower abdomen which leads to fallopian tubes or oviducts leading to the uterus(womb). Ovaries produce ovum which is transferred to the uterus with the help of fallopian tubes. The uterus has triangular shaped uterine cavity responsible for implantation and growth of zygote. It opens into the vagina through the narrow cervix. Cervical canal along with vagina forms the birth canal.
So, the correct option is 'a-cervix, b-uterine cavity, c-fallopian tube, d-ovary'.