I choose none of the options, the answer is in the Bible to what type of tree, it is not a literal tree, it is not literal fruit, can you not use the Spirit to understand the Bible? Satan is called a tree as well in Ezekiel, just apply the metaphorical sense, Satan was the most beautiful tree in the Garden, he was called nachash - "enchanter" or "magician", being a fallen angel he retained many of his immortal powers and beauty, his tree was in the midst of the Garden. God had told Adam and Eve to be 'fruitful', but not that fruit, do not eat of that fruit, 'neither touch it', 'touch' is naga, the Hebrew naga if you analyse it in connotation means to 'lie with', to 'lay down closely with', its a polite way of saying sexual intercourse'....Eve cannot have sexual intercouse with an apple or a pomegranate...."The serpent (nachash) 'beguiled' (nawshaw), which means seduced.