Refer to the Graph in Infographic 3

Refer to the graph in Infographic 3.What does the figure show?

A) fish catch in the 1960s containing mostly lower-trophic-level fish,suggesting that higher-trophic-level fish populations had been depleted
B) the size of fish catch that could be harvested in any given year without decreasing the yield in future years
C) the decrease in the size of the bycatch of different trophic levels over time as fishing technology improved
D) a plot of the Marine Trophic Index from 1950 to 2006,which is a measure of the average trophic level of fish taken in a given year and which is an indicator of the status of a marine ecosystem
E) the annual size of the cod harvest from 1950 to 2006