The following question(s) relate to the data table below, showing typical fluctuating pH and dissolved oxygen levels in a fish pond with a heavy concentration of algae over a 24-hour period.TimeOxygen (ppm)pH2 a.m.4.57.74 a.m.2.87.26 a.m.2.26.88 a.m.2.56.810 a.m.3.97.2Noon6.57.72 p.m.10.08.34 p.m.12.18.86 p.m.13.19.28 p.m.13.09.210 p.m.12.08.8Midnight10.88.3What is a possible reason for oxygen to be so low by the end of the night?
A. Fish consume oxygen during the night, and oxygen starts to run out by dawn; algae are not linked to the low oxygen.
B. Algae produce oxygen as a by-product of photosynthesis during the day, but not at night, so oxygen runs out by the end of the night; in addition, fish continue to consume oxygen during the night, which further reduces the oxygen by the end of the night.
C. Algae produce oxygen as a by-product of photosynthesis during the day, and not at night, so oxygen runs out by the end of the night; fish are not linked to the low oxygen.
D. Neither fish nor algae or linked to the low oxygen found at the end of the night.
Answer: B
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