From the passage the reader can infer the other has the opinion that

People are not always what they seem

the correct answer is c. he speculates on what might happen at given points in the future in a world without people. alan h. weisman is an american author, professor, and journalist. authors organize their information with a purpose. they present their ideas in an organized way. this is called text structure. weisman uses text structure so as to improve overall comprehension and to prove his points.