To be effective, a literary symbol should be:a) something everyone recognizes b) both itself and something more c) a poetic image from nature d) an...

I do not think that you need to choose among the four choices. An effective literary symbol can be anyone of those in addition to a few more. Let me go through your choices.

1. if people recognize the literary symbol, then it is effective to some degree. Also a recognizable symbol does not need to be commonplace. For the idea of redemption has been done so much, but if it is done well, it is powerful.,

2. A literary symbol should have multiple levels of meaning. This makes it multi-perspectival and applicable to different types of people.

3. Nature has always been a great way to create a literary symbol, but we should not limit it to this, especially in the modern world. So, I would say that this is the weakest.

4. The main character should be, in my opinion, some sort of symbol,  and other symbols could point to the main character, but it does not  have to.