Question

Which of the following is a true statement?

• A. $\left\{a\right\}\in \left\{a,b,c\right\}$
• B. $\left\{a\right\}\subseteq \{a,b,c\}$
• C. $\varphi \in \{a,b,c\}$
• D. None of these

Answer 1

The correct option is B

$\left\{a\right\}\subseteq \{a,b,c\}$

Explanation for the correct option

For option (b)

Given $\left\{a\right\}\subseteq \{a,b,c\}$

i.e., a set $\left\{a\right\}$ is a subset of the set $\{a,b,c\}$.
Explanation for incorrect option

For option (a)

Given $\left\{a\right\}\in \left\{a,b,c\right\}$

i.e., a set $\left\{a\right\}$ belongs to the set $\{a,b,c\}$.

It is not a correct statement

For option (c)

Given $\varphi \in \{a,b,c\}$

i.e., an element $\varphi$ belongs to the set $\{a,b,c\}$.

It is not a correct statement

Hence, the correct option is an option (b).