The width of a dowla is generally kept between 30 to 60 cm and its height above the road level should invariably be more than A. 10 cm B. 20 cm C. 30 cm D. 40 cm

10 cm
20 cm
30 cm
40 cm

The correct answer is C. 30 cm.

A dowla is a type of beam that is used in construction. It is typically made of wood or steel and is used to support floors, roofs, and other structures. The width of a dowla is generally kept between 30 to 60 cm, and its height above the road level should invariably be more than 30 cm. This is because the dowla needs to be able to support the weight of the structure that it is supporting. If the dowla is too low, it will not be able to support the weight of the structure and could collapse.

Option A is incorrect because 10 cm is too low for the height of a dowla. Option B is incorrect because 20 cm is too low for the height of a dowla. Option D is incorrect because 40 cm is not the minimum height for a dowla.