Final answer:
Amastia is the medical term that refers to the absence of breast development.
Step-by-step explanation:
The term that means the lack of breast development is b) Amastia. Amastia refers to the congenital absence of one or both mammary glands, which are the glands in the female breast that produce milk for offspring. This condition can occur on its own or as part of a syndrome with other developmental issues. Mastitis refers to inflammation of the breast tissue, often caused by an infection. Mammoptosis, on the other hand, is the medical term for breast sagging. Both are unrelated to the lack of breast development.