Respuesta :

P(t) = [ 64/ (1 + 11.e⁽⁻⁰ ⁰⁸t⁾]
In 1991, t = 1, hence:

P(t) = [ 64/ (1 + 11.e⁽⁻⁰ ⁰⁸ˣ¹⁾]  =  5.7377 billion or rounded 5.74 billion
(Answer A)