Beriberi is caused by deficiency of:

Vitamin B1

The correct answer is Option (3) - Vitamin B1

• Explanation:
• Beriberi is caused by a deficiency of Vitamin B1, also known as thiamine. Thiamine is essential for the proper functioning of the nervous system and the metabolism of carbohydrates. A lack of thiamine can lead to neurological and cardiovascular symptoms. Beriberi is historically associated with diets that are deficient in thiamine-rich foods, such as whole grains, legumes, and meat.