What is the study done here classified as?

A study was done amongst 2 hospitals for the equal number of cancer patients. It was noted that hospital A higher of mortality than hospital B for treated cancer patients.

What is the study done here classified as?
A . Cohort
B . Observational
C . Retrospective
D . Case study

Answer: A

Explanation:

A cohort is a group of people who share a common characteristic or experience within (e.g., are born, are

exposed to a drug or vaccine or pollutant, or undergo a certain medical procedure].