Which of the following refers to fibrocystic breast disease?
a. progressive development of fluid-filled cysts and fibrous tissue
b. the proliferation of atypical cells with high risk of malignancy
c. benign tumors that develop after menopause
d. any tissue changes other than the normal response to hormonal changes

The correct option is a. Fibrocystic breast disease refers to the progressive development of fluid-filled cysts and fibrous tissue.

Explanation:

Fibrocystic breast disease is characterized by benign (non-cancerous) changes in fibrous tissue. These changes may include irregular lumps or cysts (Breast cysts are sacs full of fluid inside the breast) which tend to mix with the surrounding fibrous tissue, breast swelling, nipple tenderness. Fibrocystic breasts are composed of tissue that can have a lumpy or rope-like texture. Which is called "nodular or glandular breast tissue" in it, there are observable characteristics of the disease through the microscope as: a prominence of fibrous tissue, excessive growth of the cells lining the breast ducts, enlargement of the mammary lobes and the fluid-filled cysts.

advantage of using stem cells in medical research:

1.       it provides medical benefits in the fields of therapeutic cloning and regenerative medicine.

2. it provides great potential for discovering treatments and cures to a variety of diseases including parkinson disease, spinal cord injuries, diabetes, alzheimer’s disease and many more.

3. limbs and organ could be grown in lab from stem cells and then used in transplant or treat illness.

hydrogen is a compound or a single element and a element is a pure substence that cannot be separated into simpler subtances

clorine is a compound its a chemical substance that forms when two or more different elements combine

so both hydrogen and clorine are compounds