Jennifer is taking a speed reading course. She records m(t), the most number of words that she can read in a minute (wpm), after t weeks of beginning the course.

t] 1 2 3 4 5 6
m(t)]124 160 220 304 412 544

According to the table, what is the average rate of change over the interval [1, 4]?

A. 60 wpm per week

B. 180 wpm per week

C. 144 wpm per week

D. 48 wpm per week