Select the Best Translation into Predicate Logic

Multiple Choice

select the best translation into predicate logic.
-If Tortuga is a city, then some settlements are not nicely placed.

A) Ct ⊃ ∼(∃x) (Sx • Nx)
B) Ct ⊃ (∃x) (Sx ⊃ ∼Nx)
C) Ct ⊃ (∃x) (Sx • ∼Nx)
D) (∃x) [Ct ⊃ (Sx • ∼Nx) ]