Select elements of list in Manipulate

Question

How can I select elements of a list of strings {"a", "b", "c"} using Manipulate, such that when a checkbox is unchecked, only the other elements are presented?

    Manipulate[ 
     {"a", "b", "c"}, 
     Control[{"a", {True, False}}],
     Control[{"b", {True, False}}],
     Control[{"c", {True, False}}]
    ]

Answer 1

Using a custom function to specify a CheckboxBar in the Manipulate, you can do the following:

list = {"a", "b", "c"};
Manipulate[selected, {{selected, {}}, CheckboxBar[#, list] &}]

You can still change the initial value like with other control specifications by replacing the {} with {"a"} or list or such.