Final answer:
The Mississippi River delta is compared to a spider web to illustrate its complex patterns of land and water, resembling the intricate structure of a web.
Step-by-step explanation:
The author compares the Mississippi River delta to a spider web likely to reveal the intricacy and complexity of the network formed by land and water in the delta region. This analogy emphasizes how the river separates into numerous smaller channels as it approaches the ocean, spreading out and depositing sediment to create new land, much like a spider web is both intricate and expansive. The correct answer that matches with this explanation is option c) To show that the land and water form complex patterns.