Which of the Following Is an Example of Consumer Surplus

Which of the following is an example of consumer surplus?

A) Jose buys a hamburger for $2 and tells you he would not have paid a penny more.
B) John believes the price he paid for his computer was too high.
C) Mary buys a paper tablet for $2 and finds the same good at another store for $1.50.
D) Sue would have paid $15 for a new compact disc but paid only $10.
E) Anne finds a mountain bike for which she is willing to pay a maximum of $550 and the price of the bike is $600.