The correct option is C Ratio scale
The two types of scales are verbal and ratio scales. The verbal scale expresses in words a relationship between a map distance and a ground distance. Eg. 1 cm = 5 km, 1 mm = 500 m.
The ratio is the division of map scale to real-area scale, say if the scale is 1:1000 that means 1 cm in the map is equal to 1,000 cm in a particular area.