The correct answer is: Both I and II follow.
The statement says that children below five die in the cities of the developing countries mainly from diarrhoea and parasitic intestinal worms. Diarrhoea and parasitic intestinal worms are both caused by poor hygiene. Therefore, governments of the developing countries should take adequate measures to improve the hygienic conditions in the cities. This would help to reduce the number of deaths from diarrhoea and parasitic intestinal worms.
In addition, children below five years in the cities of the developing countries need to be kept under periodic medical check-up. This would help to detect and treat any cases of diarrhoea or parasitic intestinal worms early, which would improve the chances of survival.
Therefore, both I and II follow.