The correct option is C Fertilization outside and gestation inside the womb of a mother
A test tube baby is a baby which is conceived through IVF. IVF is a process of fertilisation where an egg is combined with sperm in vitro. The process involves monitoring and stimulating a women's ovulatory process, removing an ovum from ovaries and letting sperm fertilise them in a culture in laboratories. After the fertilisation takes place, the zygote is transferred into the womb of the mother.
So, a test tube is a baby which is fertilised outside the body, but grows in a mother's womb.