Select the Best Translation into Predicate Logic, Using the Following

select the best translation into predicate logic, using the following translation key:
d: Diego
s: Sean
Dx: x is on the Dean's list
Px: x is a philosophy major
Sx: x is a student
Vx: x is a valedictorian
-Exactly one student is a valedictorian.

A) (∃x) (Sx • Vx) • ~(∃y) (Sy • Vy)
B) (∀x) [(Sx • Vx) ⊃ ~(∃y) (Sy • Vy • x≠y) ]
C) ~(∃x) (∃y) (Sx • Vx • Sy • Vy • x≠y)
D) (∃x) [Sx • Vx • (∃y) (Sy • Vy • x=y) ]
E) (∃x) {Sx • Vx • (∀y) [(Sy • Vy) ⊃ y=x]}