Answer : 4. "USA"
Explanation :

GHS Index:

• About:
  
  • It is an assessment and benchmarking of health security and related capabilities across 195 countries.
  • It has been developed in partnership by the Nuclear Threat Initiative (NTI) and the Johns Hopkins Center.
    
    • NTI is a nonprofit global security organization focused on reducing nuclear and biological threats imperiling humanity.
    • Johns Hopkins Center was created to recognize the crucial role of communication in public health.