Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
The reasons that sex ratio has been unfavorable to women are:
1. Literacy levels - The low literacy levels in India especially in rural areas is a major factor responsible for low female sex-ratio.
2. Lack of awareness - The basic awareness that for any healthy society female population is equally essential as the male population is, lacks in our country and makes infant birthrates unfavourable to females.
3. Female infanticide/foeticide - Females are generally considered as burden on parents and so are many times killed either before birth (female foeticide) or after birth (female infanticide).
4. Health conditions - Per capita calorie consumption for females is extremely low for all age groups. Many small and young girls suffer from malnutrition related diseases and die at an early age.