What is the purpose of ethnical guidelines for the handling of experimental subjects?

The purpose of ethical guidelines for handling of experimental subjects is;

To ensure the safety and well-being of all living creatures in an experiment

The guidelines focus on attaching ethical principles in order to protect the dignity, rights and welfare of the research participant.

The correct answer for the question above is letter d.

Explanation:

for  example, forests have higher evapotranspiration than other ecosystems,  such  as grasslands, because of their deeper roots and greater leaf area. thus forests have a net moistening effect on the atmosphere and become a moisture source for downwind ecosystems.