The given graph shows how much nitrate `(NO_(3)^(-))` is exported from the continent towards the ocean by 16 major rivers in the world rivers in the world compared to the density of human populations living along those drainage basins (i.e., along these rivers). What interpretation can be drawn from this graph ?
A. Nitrate exported through rivers from heavily populated cities can cause eutrophication and toxic algal bloom in marine coastal regions.
B. Small drainage basins export more `NO_(3)^(-)`.
C. Drainage basins with higher populstion densities export lesser `NO_(3)^(-)`.
D. both (a) and (c )
