Karate class is trying to raise money for a trip to the national championship. They are selling "Toe Socks" as their fundraiser. The graph below shows their sales for the last three weeks.

Which statement is true?

a.) The most earned in any week was $400.

b.) The class earned twice as much in week 2 as in week 1.

c.) The mean earnings for 3 weeks was $400 per week.

d.) The class earned a total of $1,400 in the three week period.