Pronouns in the objective case may function as

modifying the base for word

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.