Which is true about the degree of the sum and difference of the polynomials 3xy - 2xy4 - 7xy and -8xy + 2x°y4 + xy?
O Both the sum and difference have a degree of 6.
O Both the sum and difference have a degree of 7.
The sum has a degree of 6, but the difference has a degree of 7.
The sum has a degree of 7, but the difference has a degree of 6.