Residents of three villages with three different types of water supply were asked to participate in a study to identify individuals who were cholera carriers. because there had been several recent deaths due to cholera, almost everyone participated in the study and underwent examination and testing. the proportion of residents in each village who were carriers was computed and compared. what is the proper classification for this study?
a. cross-sectional studyb. case-control studyc. prospective cohort studyd. retrospective cohort studye. experimental study

The correct answer is option a. "Cross-sectional study".

Explanation:

A cross-sectional study is a type of observational study used in medical and social researches. Cross-sectional studies are characterized by the analysis of data that comes from a population at a specific point of time. A research that involves studying the incidence of cholera carriers at three different villages with three different types of water supply, is an example of a cross-sectional study.

the answer is; comparing the frequency of collisions with and without the device

this makes the anti-collision system an independent variable and the collisions a dependent variable. if there are fewer collisions with an anti-collision system that without, then it can be stated that the system is a success. essentially, collisions under an anti-collision system are compared with the frequency of collisions by cars with the human drivers.