The correct option is A Most countries follow American model of constitution with a preamble.
Every Constitution begins with a short statement of its basic values called the preamble to the constitution. Most countries in the contemporary world are inspired by the American model, and choose to begin their constitutions with a preamble. Preamble of India's Constitution begins with “We the people of India”. It emphasises on the fact that our constitution has been drawn up and enacted by the people, and not handed down to them by any king or outside powers.