The positive two-digit integers k and m have the same digits, but in reverse order. Which of the following must be a factor of k + m?	Choices:
A) 6 B) 9 C) 77 D) 12 E) 14
Remember: When you take the difference between the two, it will always be 9. e.g 23-32=9, 89-98=9   and when you add both integers, the sum will always be a multiple of 11 e.g 23+32=55, 89+98= 187   77 is multiple of 11   Answer : 77
<result>C</result>
The positive two-digit integers k and m have the same digits, but in reverse order. Which of the following must be a factor of k + m?