The correct answer is B. egg. In latin ovum is the singular form for "egg", while ova is its plural form.
A. the ovary is usually called as such, its latin name derives from ovarium-ovaria and only ultimately ovum. C. The Fallopian tube is also known as the uterine tube or salpinge, from the Latin Tuba uterina. D. The cervix is also known as ectocervix (or vaginal portion of the cervix), or Latin cervix uteri, but not ovum. Thus, the correct answer is B. Egg which is actually also known and called ovum, too.