Sequence Generator transformation

What is the difference between the NEXTVAL and the CURRVAL ports of the Sequence Generator transformation? Assume that they are both connected to the input ports of another transformation.

Choose Answer

(A)
The Informatica server generates a sequence of numbers for NEXTVAL, and CURRVAL is set to NEXTVAL plus one.
(B)
The Informatica server generates a sequence of numbers for NEXTVAL, and CURRVAL is set to NEXTVAL minus one.
(C)
The Informatica server generates a sequence of numbers for CURVALL, and NEXTVAL is set to CURRVAL plus one.
(D)
The Informatica server generates a sequence of numbers for CURVALL, and NEXTVAL is set to CURRVAL plus the integer value set for the "Increment By" Sequence Generator property.