If a problem, say X$,$ is in the complexity class NP$,$ then which of the following

statements are true of X$?$

i$.$ X can be verified in polynomial time

ii$.$ X is a decision problem

iii. If an NP$-$complete problem can be solved in polynomial time, then X can be solved

in polynomial time

iv$.$ X cannot be solved in polynomial time

Indicate all true statements $($Note: More than one statement may be true. No points

awarded if you fail to indicate all true statements.$)$