Answer would be (E) None of the above. Because TRAP cuts input voltage to reset the processor in the event of loss of power.
(A) executes an RST by hardware : This will not be answer, Because RST is different Interrupt than TRAP.
(B) executes an instruction supplied by an external device through the INTA signal : Again there is a different interrupt pin called INTA. Hence It is not at all related to TRAP.
(C) executes an instruction from memory location 20H : RST $4$ executes the memory address $0020H.$ Its not TRAP.
(D). executes a NOP : This can not be the answer.
Read this for more details: http://scanftree.com/microprocessor/Interrupts-In-8085.