Consider this code: my_tuple = (5, 4, 3) Knowing that tuples are immutable, select the code fragment(s) that will result in an error. my_tuple = my_tuple + (2, 1) my_tuple[0] = 7 my_tuple. append(2) my_tuple = (1, 2, 3) Select the expression(s) that can be used as dictionary keys. {1: 2, 3: 4} O ('single',) ['a', 'b'] (1, 2.0) fred, Consider this code: d = {'a': [1, 3], 'b': [5, 7, 9], 'c': [11]} Select the expression(s) that evaluate to 3. len(a) len(d['b']) len(d['a' + 'c']) len(d['a']) len(d) - 3 len(d['a']) + len(d['c'])