Which of these is not a reason why the rate of urban growth is larger in develog countries ?
A. living in closely connected settlements is a social feature common in develog countries
B. fertility rates are generally higher in develog countries including among city dwellers
C. greater job opportunities encourage large-scale internal migration from rural areas to cities
D. reverse migration (from cities back to rural communities) can be harder in develog societies once a livelihood in a rural community is lost