A computer science student often uses public forum sites like CodeGuru, DreamInCode and StackOverflow in order to help with learning a new programming language. Which of the following is true about these kinds of learning forums?
a. Forums hinder communication because moderators of the forum delete vulgar and irrelevant posts.
b. Students should not be using these kinds of sites and should only rely on teachers to get help.
c. Public data found on these forums provides widespread access to identified problems and their solutions.
d. Data from these sites are completely copyright free and answers, ideas and concepts can be used at the will of any user.