Abelian Group : The Group which satisfy commutative properties ( a op b = b op a )
Option A: Group of all Permutations of a set is not Commutative, Because in Permuation order matters
Eample: {1,2,3}
- If we first swap 1 and 2 and then 2 and 3 we get {3,1,2}
- If we first swap 2 and 3 and then 1 and 2 we get {2,3,1}
Thus, order matters in permutations
Option B: Multiplication of two Matrices is not Commutative
Option C: Group of all 3D rotations is not Commutative because Order of rotation Matters.
Example: Rotating Clokwise 60° then Anticlockwise 30° is different from Rotating AntiClokwise 60° then Clockwise 30°
Option D: Group of all Integers Under addition is commutative because addition is commutative
a+b = b+a
Hence, Option D