Initiated in 1975, sandhill cranes must unwit- tingly cooperate in the conservationists' project to
raise endangered whooping crane chicks.
(A) sandhill cranes must unwittingly cooperate in
the conservationists' project to raise
(B) sandhill cranes' unwitting cooperation is
required in the conservationists' project to
raise
(C) the conservationists require that sandhill
cranes unwittingly cooperate in their proj-
ect of raising
(D) the conservationists require sandhill
cranes to cooperate unwittingly in their
project to raise
(E) the conservationists' project requires the
unwitting cooperation of sandhill cranes
in raising