What is an example of intrinsic motivation?

a. A goal of yours is to produce your own web page, so you take an online class to learn how to write computer code.
b. All your friends are playing a certain video game, and even though you do not like it, you play so you can be a part of the crowd.
c. To play sports at the local youth organization there are many requirements, and even though you do not like sports much, you meet the requirements so you can play sports with your friends.
d. Your teacher tells the class about his favorite book, so you choose that one to read for a book report, thinking he will be pleased.