If A = {1, 3, 5, B} and B = {2, 4}, then
(a) \(4 \in A\)
(b) \(\{4\} \subset A\)
(c) \(B \subset A\)
(d) none of these
Solution
Given,
\[ A=\{1,3,5,B\} \]
and
\[ B=\{2,4\} \]
Here, the set \(B\) itself is an element of \(A\), not the elements \(2\) and \(4\).
Therefore,
\[ 4 \notin A \]
\[ \{4\} \not\subset A \]
Also,
\[ B=\{2,4\} \]
but \(2\) and \(4\) are not elements of \(A\). Hence,
\[ B \not\subset A \]
Answer
\[ \boxed{\text{none of these}} \]
Correct option: (d)