Read the passage given below and answer the questions (121 - 128) that follow :
People are drawn to vegetarianism by all sorts of motives. Some of us want to live longer,healthier lives or do our part to reduce pollution. Others have made the switch because we want to preserve earth’s natural resources or because we’ve always loved animals and are ethically
opposed to eating them.
Vegetarianism promotes a natural way of life. But despite its implicit message of universal love and non-violence it has not spread as it should have. This may be because it usually is an inward-looking habit and is best cultivated in the mind.
Leading a vegetarian way of life helps the animal kingdom co-exist with man. The animals supply milk, manure and energy. This has been central to the Indian culture for thousands of years. A vegetarian life style is natural, multifaceted and helps self-preservation in a healthy way.
Food and health are closely related.
Vegetarian foods provide an infinite variety of flavours whereas non-vegetarian foods have hardly any taste of their own. In fact, non-vegetarian foods have to be seasoned with ingredients from the vegetable kingdom to make them palatable.

Identify the part of speech of the underlined word in the following expression.
This has been central to the Indian Culture.