The correct option is D (i), (ii), (iv)
Roads form an integral part of the transport system in India. There are two types of roads - metalled and unmetalled. Metalled roads are also known as all-weather roads. NH-7 and NH-4 form a part of the 'Corridor Project'. Apart from national highways, we have state highways, district roads and village roads. The Zilla Parishat maintains district roads. Taluk panchayats and village panchayats maintain village roads.