A. The sentence works fine. one could argue B, but a colon is used to separate a run-on or show two complete thoughts in the same sentence, so arguably B would not work either.
Yes they are correct I think.
Harry Potter's wand can be symbolized in school because it shows that, even though there is no such thing as magic, we are capable of doing great things and succeeding in school. You can relate this to Olivander's words in the first movie or book, when he said that he expects great things from Potter. One example of a great thing that you could do in school is pass all of your classes with good grades. Another example of a great thing you could do in school is understand all of the concepts you are being taught or even overcome something hard and understand it after working hard. Lastly, you might be able to compete in sports at school and win a really tough game. In the end, this all may seem like Harry's wand doing the magic, but in reality, we humans are capable of doing great things.
Hope this was good! :)
