Writing MC question

<p>August Wilson's Pittsburgh Cycle consists of ten plays, [nice of which are set in Pittsburgh's Hill District, an African American neighborhood, and each of which is set] in a different decade of the twentieth century.
(A) nine of which are set in Pittsburgh's Hill District,
an African American neighborhood, and each of
which is set
(B) nine of them arc set in Pittsburgh's Hill District,
an African American neighborhood, and each
one of them arc set
(C) nine of them being set in Pittsburgh's Hill
District. an African American neighborhood,
each of them is set
(D) nine of the plays set in Pittsburgh's Hill District,
an African American neighborhood, and the
settings of each one is
(E) nine set in Pittsburgh's Hill District. an African
American neighborhood, and each have their
setting </p>

<p>I choose D but the answer is A. Is D in any way wrong, or A just sounds better? I have never seen "and" before "each of which" (I think "and" is only used to mark a new equivalent phrase, not a subordinate one).</p>

<p>Thank you.</p>

<p>Cut out all the extraneous information in the sentence:</p>

<p>August Wilson’s Pittsburgh Cycle consists of ten plays, nine of which are set in Pittsburgh’s Hill District, an African American neighborhood, and each of which is set in a different decade of the twentieth century.</p>

<p>It consists of plays, which are set in the setting, and each of which is set in the setting.</p>

<p>Which refers to the plays in the second phrase, and each of which refers to ** each of the plays**.</p>