Which data structure consists of nodes connected by edges and includes a root node?

The data structure that consists of nodes connected by edges and includes a root node is a tree. In tree structures, one node is designated as the root, and all other nodes are connected to the root in a hierarchical fashion. This organization allows for efficient searching, insertion, and deletion operations. Each node in the tree can have child nodes, creating a branching pattern that represents relationships in the data.

Trees are widely used in various applications such as representing hierarchical data (like file systems), implementing binary search trees to maintain sorted data, and facilitating quick lookups and data organization. The key characteristic of a tree is that it is acyclic, meaning there are no cycles, and it has a defined structure with a single path from the root to each node.

In contrast to trees, other data structures listed—like arrays, queues, and graphs—do not inherently have a defined root node structure or the same hierarchical relationships. Arrays are linear collections of elements, queues are linear data structures that follow FIFO order, and graphs consist of nodes connected by edges but may not have a root node or a hierarchical relationship. Therefore, the defining feature of having a root node alongside connections among nodes clearly identifies trees as the correct answer in this context.