The term CETI stands for Communication of Extraterrestrial Intelligence and this essay is written by Lewis Thomas. Based on this essay, the tone that mostly covers the whole essay is SCIENTIFIC because this focuses about the persuasion regarding his research. The answer would be option C.
Lewis Thomas' essay, named <em>''Ceti''</em>, was about a relatively near star allows Earth to have life, and possible life in other systems with near star like ours.
It's often futile to try to convince people that they should adopt a particular political position, but if you try, make sure to appeal to logic. Try to eliminate as much emotion from your argument as possible.