What is the rhyme scheme of this poem?
"Old Kaspar took it from the boy,
Who stood expectant by;
And then the old man shook his head,
And with a natural sigh,
"'Tis some poor fellow's skull," said he,
"Who fell in the great victory."
1. ABCDBB
2. ABBCDD
3. ABCBDD
4. AABCDD