Which Statement Is MOST Accurate Given the Text's Discussion of the Gate-Control

Which statement is MOST accurate given the text's discussion of the gate-control theory of the experience of pain?

A) The pain gate is opened by bottom-up mechanisms; it is also closed in a bottom-up fashion.
B) The pain gate is opened by bottom-up mechanisms; it is closed in a top-down fashion.
C) The pain gate is opened by bottom-up mechanisms; it may be closed in either a top-down or a bottom-up fashion.
D) The pain gate may be opened by either bottom-up or top-down mechanisms; it may be closed in either a top-down or a bottom-up fashion.