ALGEBRAIC APPROACH:Things to know:
#1:
---------> |a| = a, when a>=0
---------> |a| = -a, when a<0
#2:
|x|=|y|
Case 1: When x>0 & y>0
x=y
Case 2: When x>0 & y<0
x=-y
Case 3: When x<0 & y>0
-x=y
Case 4: When x<0 & y<0
-x = -y
Case 1 & 3 are same equations. Case 2 & 4 are same equations. Thus, |x|=|y| can give one of the below two equations.
1) x = y
2) x = -y
Back to the question:Similarly, |a-b|=|b-c| will yield
Case 1) a-b = b-c---------------> a+c=2b-----------> c =2b-a
Thus, |a-c|= |a-(2b-a)|=|2a-2b|=|2(a-b)|=2|a-b|=2*2=4.............(Question stem gives |a-b|=2)
|a-c|=4
Case 2) a-b = c-b
Thus, a=c----> a-c=0
Statement 1) a<b<c
Thus, \(a \neq c\) since a<c... Case 2 is not applicable.
Case 1 it is... |a-c|=4
Sufficient.
Statement 2) c-a>c-b
Thus, a<b....
This information doesn't give us any information to eliminate one of the above cases.
Insufficient.
Answer A