Let R be the region between the graph y = sqrt(x) and the line y =x, 0 < x < 1. A solid has R as its base, and

the cross sections perpendicular to the x-axis are squares. Then the volume of this solid is:

a) 8/15

b) 1/15

c) 8/25

d) 1/30

e) 7/25

f) 1/6