Which statement below best applies to the following expression?
-4√11 - 5√13
a.
the two terms cann√ot be combined because the radicands are not identical, and cannot be simplified so that they are identical
b.
the two terms cannot be combined because the indices are not identical
c.
the two terms cannot be combined because the resulting value of the subtraction would be negative
d.
the two terms may be combined