SAT Mathematics Practice Test 3

Let I be the initial savings.
If each successive year, 1% of the current value is added to the value of the account, then after 1 year, the amount in the account will be $\mathit{I}+0.01\mathit{I}=\mathit{I}\left(1+0.01\right);$
after 2 years, the amount in the account will be and after t years, the amount in the account will be $\mathit{I}\left(1+0.01\right)\mathit{t}$.
This is exponential growth of the money in the account.
Choice A is incorrect.
If each successive year, $2\%$ of the initial savings, I, is added to the value of the account,
then after t years, the amount in the account will be $\mathit{I}+0.02\mathit{I}\mathit{t},$ which is linear growth.
Choice B is incorrect.
If each successive year, $1.5\%$ of the initial savings, $\mathit{I}$, and $100$ is added to the value of the the account,
then after t years the amount in the account will be $\mathit{I}+\left(0.015\mathit{I}+100\right)\mathit{t}$, which is linear growth.
Choice D is incorrect.
If each successive year, $100$ is added to the value of the account, then after t years the amount in the account will be $\mathit{I}+100\mathit{t}$, which is linear growth.