Final answer:
In typical fashion of James Brown's backup band, d. the horn section was the most active and varied instrument(s).
Step-by-step explanation:
In the typical fashion of James Brown's backup band, the most active and varied instrument(s) heard is the horn section. James Brown, often referred to as the "Godfather of Soul," was known for his dynamic stage presence and powerful vocals, but equally important to his performances was the tight, punchy sound provided by his horn section. This section often included trumpets, saxophones, and trombones, which added a potent blend of rhythm and melody that became a hallmark of James Brown's energetic funk style. The horn players were not only responsible for the brassy stabs and riffs but also for punctuating the groove and accentuating the performance's intensity, making them indispensable to the overall sound.