2012 Morning Mock Q35

Can anyone explain the answer? Also, how should we interpret Exhibit 2? We got value of the test statistic, standard error, and t and sigificance of t?

So do we just say test stat / std error = t and comapre that to sigificance of t?

Is sigificance of t same as critical value of t?

So how does the answer apply here? In this case shouldn’t all of them reject H0 thus there is no unit root? Thanks so much in advance.