Which of the following will modify a string s= "dcba" to become "abcd"? sorted(s) s=sorted(s) s.sorted() None of the above Given grade = \{'A': [['Alan', 78], ['Tom', 89]], 'B': [], 'C': [ ['Jay',86]]\} Which expression returns Tom's score which is 89 ? \begin{tabular}{c} \hline grade [0][1][1] \\ \hline grade['A'][1][1] \\ \hline grade {0][1][1] \\ \hline grade [A]1][1] \\ \hline \end{tabular}