The correct option is C Both (b) and (d)
Given A={2,3,4,5,6,7},B={2,4,7,8},C={2,4}
Let us find which of the following statements are true.
(a) Consider B⊂A
Since 8∉A,B⊈A
Therefore the statement "B⊂A" is not true.
(b) Consider C⊂A
Since 2,4∈A,C⊂A
Therefore the statement "C⊂A" is true.
(c) Consider B⊆C
Since 7,8∉C,B⊈C
Therefore the statement "B⊆C" is not true.
(d) Consider C⊂B
Since 2,4∈B,C⊂B
Therefore the statement "C⊂B" is true.
Thus both (b) and (d) are true.