AlmostAtheist:
1) Teach all "how did it get here" theories, presenting the why's and why not's of all sides. Give the students various view points.
Good idea, but not in a science class. A religion or philosophy class might be more appropriate. They could teach students about biblical creationism as well as other origin myths.
2) Teach only what has been accepted by the scientific community.
That's the function of a high school science class. It's not there to present every possible belief and theory. It's there to give children a grounding in the basics of modern science. Evolution is the basis of modern biology and should be taught as such. There really is no debate over it except in the more backwards areas of the USA.
b) bad, because it causes students to believe evolution is the only idea held by anybody
Students should definitely be made aware that there are people who do not believe in evolution. Whether it is appropriate to do so in a science class is debatable. Should a history class studying World War II be made aware of the beliefs of Holocaust deniers?
I think it's important to teach children critical thinking skills. That way, when they are faced with the subtle deceptions of creationists, holocaust deniers and second-hand car salesmen, they will be better equipped to deal with them.