Fact 1: Insulated material can be used for keeping warm.

Fact 2: Warm chain is the key to newborn survival.

Given the two facts above, answer the question "What is the key to newborn survival?" with the following options: 
- deoxyribonucleic acid
 - insulated material
 - empty nest
 - food and shelter
 - cold bed
 - Thyroid-stimulating hormone
 - chemical messengers
 - eating fish


 

  insulated material       