Estimate the population of Nisos in the year 2050.
$\text{(A)}\ 600 \qquad \text{(B)}\ 800 \qquad \text{(C)}\ 1000 \qquad \text{(D)}\ 2000 \qquad \text{(E)}\ 3000$
The population triples every $25$ years from $200$, and there are $50$ years between $2000$ and $2050$, so we will have $200\times3=600\times3=1800$.
This is an underestimate, since there are actually $2$ more years for the island's population to grow.
Therefore, $1800$ can be rounded to $\text{(D)}\ 2000$