Babies born through .......... are called as test tube babies.

$\text{Correct option:B}$ 

$\text{Solution:}$

$\text{Option (A)}$

$?$ During Internal fertilization, the body of a female have a healthy reproductive system due to which fusion of gametes takes place inside the ampullary-isthmic region of fallopian tube and results in the production of zygote which then gets implanted in the uterus for further development.

$\text{Option (B)}$

$?$ IVF  stands for in vitro fertilization. In this process,ovum is collected from the female and semen is collected from the male ,and these gametes are fused to form a zygote outside the body in almost similar conditions as that found in the female body.

$\text{Option (C)}$

$?$ Option (b) is only correct.

$\text{Option (D)}$

$?$ Option (b) is correct.

$\text{Hence, the correct option is (B)}$