The Circulation M, in Thousands, of a Magazine Depends on the Time

The circulation M, in thousands, of a magazine depends on the time t, in years, since initial publication.The following relationship is valid over the first 7.00 years: . When did magazine circulation reach a maximum, and what was the maximum circulation? Round your answers to two decimal places.
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A) The maximum circulation of 4.67 thousand occurred 54.81 years after initial publication.
B) The maximum circulation of 54.81 thousand occurred 4.67 years after initial publication.
C) The maximum circulation of 2.89 thousand occurred 57.70 years after initial publication.
D) The maximum circulation of 57.70 thousand occurred 2.89 years after initial publication.