问题：
[单选题]If the main body is demonstrated following the "problem and solution" patten, what might be the best visual?
ATime line.
BSide by side demonstration graphs.
CPictures and graphs.
[单选题]If the main body is demonstrated following the "problem and solution" patten, what might be the best visual?
ATime line.
BSide by side demonstration graphs.
CPictures and graphs.
