Didn't understand the question and logic asked.

Question

Which of the following is not REL?

• A. $L$ = {$<M>$ | $L(M)$ = $\phi$, M is a TM}
• B. $L$ = {$<M>$ | $L(M)$ $\neq$ $\phi$, M is a TM}
• C. $L$ = {$<M, x>$ | M halts on x}
• D. $L$ = {$<M, x>$ | accepts x}

Comments

The questions asks for which language is not $REL$.

We will use Rice Theorem and check if any property is non-monotonous

$1.$ Say, $M=\left \{ \right \} $ So, $L(M)=\phi$

So, $L(M)=T_{yes}$

$M_1=\left \{ 1,2\right\}$ So, $L(M_1)\neq\phi$

So, $L(M_1)=T_{no}$

as $M\subset M_1$ then $T_{yes}\subset T_{no}$

So, $L = \left\{ M\,|\,L(M)=\phi\right\}$, is non-REL

Correct me if i'm wrong

Ref : here

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@Shobhit Joshi

acc to rice theorem 

Rice’s theorem the language describing any nontrivial property of Turing machine is not recursive

What you mean by non trivial property here ???

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For a property of recursively enumerable set to be non-trivial, there should exist at least recursively enumerable languages, (hence two Turing machines), the property holding for one ($T_{yes}$ being its TM) and not holding for the other ($T_{no}$ being its TM)