Answer:
a. True
Step-by-step explanation:
Cardiac plexus is a network of nerves present at the base of the heart. Sympathetic fibers of cardiac plexus originate from the cardiac nerves and they arise from the sympathetic trunk. Parasympathetic fibers arise from the vagus nerve's cardiac branches. In this way the heart is innervated by both sympathetic and parasympathetic fibers. Medulla in brain controls both the branches.