The sympathetic and parasympathetic divisions of the ANS:
a. never innervate the same organ.
b. always have opposing effects.
c. cannot work independently.
d. may work together, each controlling a stage of a complex process.

B. ALWAYS HAVE OPPOSING EFFECTS

Explanation:

The autonomic nervous system controls the internal organs of the body, cardiac and smooth muscles and various glands. It does so by the actions of the two divisions of the autonomic nervous system; the sympathetic and the para-sympathetic nervous system which are important in nervous responses to changes in the internal environment of the  body. The sympathetic division of the ANS is involved in the changes associated with increased metabolism and are involved in fight-or-flight response. The parasympathetic divisions are involved in relaxation or inhibiting the effects of the sympathetic divisions. For example the heart receives sympathetic innervation which cause increased heart rate and the parasympathetic innervation which cause reduction in heart rate. The heart receives innervation from both the two divisions and the effects of both is opposite in order to ensure activity of the organ.  The two divisions can innervate the same organ as in the case of the heart and other organs.