when some one say the error is within 25 mv over rangethis m

when some one say the error is within \"\"\"2.5 mv over range\"\"\"..this means that +- 2.5 or the total of +- (ex: +-3 have total 6) ???
answer1: +-1.25 so the total is 2.5
answer2: +- 2.5 so the total is 5
which is the correct answer?

so linearity error is +- 2.5 or +-1.25?? also for sensitivity error is it +-2 or +-1??

Answer 2 is correct..because error is specified to be overrange..we consider +- 2.5 rather than +-1.25