_________change the blockchain layout from a linearly sequential model.

Tree Chainsmodify the standard blockchain structure from a linear sequence to a tree-like structure, where blocks can have multiple branches instead of forming a single sequential chain. This structure can improve scalability and enable parallel processing, as multiple chains can be validated simultaneously.

Key Details:

Tree Structure: In tree chains, blocks can have multiple child blocks, which allows transactions to be processed across several branches concurrently. This reduces bottlenecks associated with linear block validation and enhances throughput.

Benefits Over Linear Chains: Traditional blockchain models process blocks in a strict sequence. Tree chains allow for more flexibility and higher transaction throughput, as multiple blocks can be validated simultaneously across different branches.

Use Cases: This structure is advantageous for complex applications that require parallel transaction processing, such as large-scale blockchain networks or systems needing high transaction speeds.

Thus,D. Tree chainsis the correct answer, as it refers to the blockchain model that diverges from a linear structure.