Paragraph 6: In many parts of the ocean where bacteria and krill congregate in high densities tofeed on suspended particulate material, their metabolic activities deplete the water of availableoxygen, thereby creating the oxygen-minimum layer. Those organisms that exploit the detritus inthis layer or feed on other organisms found there must cope with low oxygen levels. The fish, thekrill, and the shrimp associated with this layer characteristically have large gills and blood that ishighly efficient at absorbing any available oxygen. Typically, such animals are also sluggish andadopt an opportunistic policy rather than actively hunting for prey. This way, they conserve energyand reduce their oxygen requirement. Their skeleton and musculature are reduced, and their bodyshape and form is subordinated to the need to remain floating in the water column with theminimum of muscular effort.7. Which of the sentences below best expresses the essential information in the highlightedsentence in the passage? Incorrect choices change the meaning in important ways or leaveout essential information.A: The oxygen-minimum layer occurs where high concentrations of bacteria and knll have depletedthe water of oxygenB: In many parts of the ocean, bacteria and krill gather in high densities to feed on suspendedparticulate matterC: Only krill and bacteria are common in the oxygen-minimum layer, because they need lessoxygen than other organisms.D: High densities of suspended particulate matter exist in the oxygen-minimum layer in many partsof the ocean.8. Which of the following can be inferred from paragraph 6 about predators in theoxygen-minimum layer?A: They are generally stronger than predators in other parts of the oceanB: They generally wait for their prey to come to themC: They spend most of their time swimming around, searching for preyD: They deplete less oxygen from the water than their prey do