The chief factor associated with ill health in childhood is

A) size of family.
B) lack of health insurance and access to health care.
C) lack of daycare.
D) stress that helps to boost the immune system's responsiveness.

Lack of Health Insurance

The absence of healthcare coverage, which can result in limited access to medical services and financial hardship due to medical expenses.

Ill Health

A state of poor physical or mental condition; not being well.

Chief Factor

The primary or most significant element influencing a particular outcome or situation.