The relation R in the set A = {1, 2, 3} given by R = {(1, 2), (2, 1)}…

A = {1, 2, 3}     R = {(1, 2), (2, 1)}

for every (a, a) ∈ A

(a, a) ∈ R → not true (NOT reflexive)

for every (a, b) ∈ R

(b, a) ∈ R (True ⇒ Symmetric)

as (1, 2) ∈ R ⇒ (2, 1) ∈ R, true

Option 2 → Symmetric