Answer:
D. Series, Parallel, and Series/Parallel
Step-by-step explanation:
Categorized according to topology, circuits are ...
Series, Parallel, and Series/Parallel
__
Circuits can also be categorized according to the nature of the voltages and currents found in them. These categories would include AC, DC, and some mixture of AC and DC.
The terms "simple" and "direct" and "indirect" don't seem to have any defined meaning in this context.