The correct option is D Q⊆R
Given,
P={2,4,6,8,10,12},Q={4,6,8} and R={4,6}
Since, each element of set Q is in set P,
Therefore, Q⊆P[Q is subset of P].
Since, each element of set Q and Set R in set P.
P is superset of set Q and set R.
Therefore, P⊇R and P⊇Q
Hence, option a, b and c are correct.
'8' is not in set R. Hence, set Q is not subset of R.
Hence, correct option is Q⊆R.