Final answer:
The deficiency disease associated with Vitamin B3 (niacin) is pellagra (option a) , which presents as the "3 Ds" - Dermatitis, Diarrhoea, and Dementia, and can be fatal if not treated.
Step-by-step explanation:
Vitamin B3 (Niacin) Deficiency
The deficiency disease of Vitamin B3, also known as niacin, is pellagra. Pellagra is characterized by symptoms commonly referred to as the "3 Ds", which are Dermatitis, Diarrhoea, and Dementia. These symptoms include headache, forgetfulness, depression, and anxiety. If pellagra is left untreated, it can result in a fourth 'D', Death. It is important to note that other deficiency diseases such as scurvy, beriberi, and rickets result from deficiencies in different vitamins.
Scurvy is caused by a lack of Vitamin C and is characterized by weakened bones and capillaries, leading to easy bruising and poor wound healing. Beriberi results from a deficiency in thiamine (Vitamin B1) and can lead to nervous system issues and cardiovascular complications. Rickets is a result of Vitamin D deficiency, which affects the proper development of bones in children.