Lauren simplified the expression (mm)
 as shown.
 -7+(-5) = m 12
 = m
 m!
 Which statement explains Lauren's error?
 OOOO
 O She should have subtracted the exponents instead of adding them.
 She should have multiplied the exponents instead of adding them.
 She should have found -2, not-12, as the exponent when she added.
 O She should have written m-12 as-m12