PLEASE HELP FOR 50 POINTS.
Tim wants to study how air currents affect weather patterns around the Earth. During his study, he makes several assumptions based on accepted scientific knowledge, including


-the Earth is round;

-warm air rises over cooler air;

-the Sun is the main source of energy for many Earth processes.


Is it acceptable for Tim to make these assumptions during his investigation?


A. Yes; when performing a scientific investigation, accepted scientific facts can be assumed to be valid.


B. Yes; a scientific investigation can be based on any assumptions, as long as they are clearly stated.


C. No; Tim must scientifically prove that all of the assumptions are valid as part of his investigation.


D. No; assumptions are never permitted in a scientific investigation.