Expand region increases the selected region by semantic units. Just
 keep pressing the 'C-=' key until it selects what you want.
 The notion of "semantic" is language-sensitive.
 .
 Example: editing
 .
 (setq alphabet-start "abc def")
 .
 With the cursor at the `c`, it starts by marking the entire word
 `abc`, then expand to the contents of the quotes `abc def`, then to
 the entire quote `"abc def"`, then to the contents of the sexp `setq
 alphabet-start "abc def"` and finally to the entire sexp.