In geography, “scale” refers to
a. the depth of inquiry or the amount of details
b. an instrument used to weigh things
c. how someone perceives or understands something
d. the way that someone looks at something

As we know about geography course,the scale of a map is the ratio of a distance on the map to the corresponding distance on the real ground.Scale may have different varieties, but for our case, It can be refereed as an instrument of measurement. So the answer of this question is the choice B: an instrument used to weigh things.

The answer is that they depend on rainfall for their crops to grow. hope this .