It is given that the area of a triangle is A. The values of its perimeter, in radius, circumradius and the average of the lengths of the medians are respectively, p, r, R and d. The ratio A : p is equal to:

A

r : 1

B

(R+r)$$^2$$ : d

C

r : 2

D

(R - r)$$^2$$ : r