Select the sentence with the correct punctuation.
1. I don't see the point of lengthy homework: Three problems offer practice and show mastery just as well as twenty problems.
2.I don't see the point of lengthy homework Three problems offer practice and show mastery just as well as twenty problems.
3.I don't see the point of lengthy homework, Three problems offer practice and show mastery just as well as twenty problems.
4.I don't see the point of lengthy homework; Three problems offer practice and show mastery just as well as twenty problems.