The correct answer is A. Ambala.
Ambala has the highest road density of metalled roads in Haryana. The road density of Ambala is 100.3 km/100 sq km. This means that there are 100.3 km of metalled roads for every 100 sq km of area in Ambala.
Panchkula has a road density of 98.4 km/100 sq km. Kaithal has a road density of 96.2 km/100 sq km. Jhajjar has a road density of 94.1 km/100 sq km.
The road density of a district is the total length of all roads in the district divided by the total area of the district. The road density is an important indicator of the development of a district. A high road density indicates that the district has a good infrastructure and is well-connected to other parts of the state.
The road density of Haryana is 95.1 km/100 sq km. This means that there are 95.1 km of metalled roads for every 100 sq km of area in Haryana. The road density of Haryana is higher than the national average of 60.6 km/100 sq km. This indicates that Haryana has a good infrastructure and is well-connected to other parts of the country.