Step 1: Sentence 7 introduces the idea that competition in an industry is not random. The next sentence should explain why or how competition arises.
Step 2: Sentence B, starting with "rather," directly refutes the idea of coincidence, stating that competition is rooted in the industry’s economic structure, making it a logical follow-up to sentence 7.
Step 3: Sentence D elaborates on B by specifying that competition depends on five basic competitive forces, providing a detailed explanation of the economic structure.
Step 4: Sentence A explains that these forces (from D) determine the industry’s profit potential, connecting the competitive forces to profitability.
Step 5: Sentence C states that not all industries have the same potential, setting up sentence 6, which concludes that different industries sustain different profitability levels due to these forces.
Step 6: The sequence BDAC flows logically: competition is not random (7), rooted in economic structure (B), defined by five forces (D), which determine profit potential (A), varying by industry (C), leading to different profitability levels (6).
Verification: Options like DABC place D before B, disrupting the explanation of economic structure, and ABCD starts with profit potential prematurely.