Geriatric psychiatry highlights the biological and psychology aspects of normal ageing, acute and chronic illness and the biological and physiological aspects of the primary psychiatric aspects of older age.
Hence the option a is not correct.
Gerontology is the study of social, cultural, psychological, cognitive and biological aspects of ageing.
Hence the option b is not correct.
Geropsychology is a discipline of psychology that deals with the issues of ageing, mainly the psychological problems that are unique to older age.
Hence the correct option is.