One model of Earth's population growth is P(t) = 64/(1 + 11e^(0.8t)), where t is measured in years since 1990, and P is measured in billions of people. Which of the following statements are true? Check all that apply.
A. In 1991, there were 5.74 billion people, according to this model.
B. The population of Earth will grow exponentially for a while but then start to decrease.
C. The population of Earth is growing at a rate of just under 8% per year.
D. The carrying capacity of Earth is 64 billion people.