Which among the given correctly explains the phenomenon of 'Test Tube Baby' -

When the fertilisation is external & development is internal.. In vitro fertilization (IVF) is a process by which an egg is fertilized by sperm outside the body: in vitro. Test tube baby is born from in vitro fertilization. When a woman's natural cycle is monitored to collect a naturally selected ovum (egg) for fertilization, it is known as natural cycle IVF. The fertilized egg (zygote) is then transferred to the patient's uterus with the intention of establishing a successful pregnancy.