The correct answer is option b. uniform spaced.
The blue-stem is a medium sized grass, which grow in prairie. These grasses are generally continuous spread in a uniform distribution pattern. The group of the grasses are equally spaced, and more or less aligned with respect to one another. Hence, they are said to be uniformly spaced.
As they are continuous, and not randomly distributed, so, they cannot be said as randomly distributed or clumped.
