The total fertility rate (TFR) of 4.0 indicates that, on average, each woman in that country is having 4 children. A TFR of around 2.1 is typically considered the replacement level, which means that the population would remain stable over time, assuming no significant changes in mortality or migration.
Since a TFR of 4.0 is well above the replacement level, it most likely indicates that the population will experience growth.
Therefore, the best answer is:
D. The population likely is growing.