Casey is reading a book for a book report. At 3:30 P.M., he started reading where he had left off the day before.

At 5:30 P.M. he was on page 160. At 8:00 P.M. he was on page 280. If reading the book is modeled by a linear function, what page did Casey start on at 3:30 P.M.?

A) 60
B) 64
C) 70
D) 74