Need with geometry (updated)

what is the value of ac – ef?

m. a. b. c. d. o. e. f. g. h. n

-5. -4. -3. -2. -1. 0 1 2. 3. 4. 5

choices:

a. -5
b. -3
c. -1
d. 1 < correct answer, just took the test

i think it might be 1 but i don't know for sure.

my reasoning:

|-4 - (-2)| - |1-2|
|-4+2| - |-1|
|-2| - |-1|
2 - 1
1