Gerontology (B): Gerontology is the clinical take a look at of growing old and the issues that elderly people may face. It encompasses the biological, psychological, and social elements of getting older.
Osteology (A): This is the have a look at of bones.
Etiology (C): This is the have a look at of the reasons of diseases.
Teratology (D): This is the have a look at of abnormalities of physiological improvement.