At the beginning of the year, a developing country had a population of $1\,000\,000$, with a birth rate of $16.0$ per thousand per annum and a death rate of $8.0$ per thousand per annum. By the end of the year, the population had risen to $1\,005\,000$. What might account for this change in the population?
- AThe birth rate rose.
- BThe death rate fell.
- CThere were $3000$ emigrants.
- DThere were $5000$ immigrants.