A continuous function r satisfies the following.
• r(x)>0 on 0<x<2 and the region bounded by the graph of r and the x-axis over that interval has area 6.
• r(x)<0 on 2<x<5 and the region between the graph of r and the x-axis over that interval has area 4.
• r(x)>0 on 5<x<6 and the region bounded by the graph of r and the x-axis over that interval has area 3.
Define R(x)=∫0xr(t)dt for 0≤x≤6. At which of the following x-values does R attain its absolute maximum on [0,6]?
a) x=6
b) x=5
c) x=2
d) x=0