OG详解-OG1 数学2 Q15

Choice A is correct. For an exponential function of the form E(t)= a (b)^t , where a and b are constants, the initial value of the function—that is, the value of the function when t = 0—is a and the value of the function increases by a factor of b each time t increases by 1. Since the function E(t)= 5(1.8)^t  gives the estimated number of employees at a restaurant and t is the number of years since the restaurant opened, the best interpretation of the number 5  in this context is the estimated number of employees when t = 0, or when the restaurant opened.
Choice B is incorrect and may result from conceptual errors.
Choice C is incorrect and may result from conceptual errors.
Choice D is incorrect and may result from  conceptual errors.