The answer is b. Fallopian tube.
A zygote is the female egg fertilized by male sperm. Human reproduction is sexual which mean it needs both male and female gamete. Female egg leaves the ovary and goes to the Fallopian tube, which connects ovary to the uterus. Male sperm swims through vagina and uterus to the Fallopian tube, too. In Fallopian tube, male sperm fuses into female egg and zygote is created.