question_answer

If \[U=\left\{ 1,\text{ }7,\text{ }11,\text{ }13,\text{ }15,\text{ }18,\text{ }21,\text{ }32,\text{ }35,\text{ }39 \right\},\]then which of the following is not a subset of U.

A)  \[A=\left\{ 1,\text{ }18,\text{ }7,\text{ }35 \right\}\]

B)  \[B=\left\{ 21,\text{ }11,\text{ }35,\text{ }7,\text{ }13 \right\}\]

C)  \[C=\left\{ 7,\text{ }18,\text{ }32,\text{ }11 \right\}\]             

D)  \[D=\left\{ 1,\text{ }7,\text{ }18,\text{ }15,\text{ }13,\text{ }2 \right\}\]

E)  None of these