In one study, participants viewed two non-word strings . . . that appeared simultaneously on a computer screen, and on each trial had to select the non-word that they perceived to be more humorous. Which topic sentence would best introduce this paragraph?

A. Non-word strings are a series of letters that look and sound like words but have no meaning.
B. Non-word strings have interested scientists for decades, and they are the foundation of comedy.
C. Scientists are interested in what makes people laugh, and they conduct experiments to determine what is considered funny.
D. Scientists are responsible for conducting studies where participants are invited to be a part of the research process and experimentation.

The rich natural resources made the sacramento valley a "garden of eden." permanent villages were established about 8,000 years ago. which choice combines these two sentences from paragraph two to achieve a coherent flow of ideas? a) the rich natural resources made the sacramento valley a "garden of eden" and permanent villages were established about 8,000 years ago. b) permanent villages were established about 8,000 years ago and the rich natural resources made the sacramento valley a "garden of eden." c) the rich natural resources made the sacramento valley a "garden of eden; " and so the permanent villages were established about 8,000 years ago. d) because of the rich natural resources which made the sacramento valley a ‘garden of eden,’ native americans established permanent villages there 8,000 years ago.