Which of the following is an example of an algorithm used in travel?

Dijkstra's algorithm is a well-known method for finding the shortest paths between nodes in a graph, which makes it particularly useful in the context of travel and navigation. When you consider scenarios such as mapping routes on a map, airline flight paths, or logistics in transportation, Dijkstra's algorithm can effectively determine the most efficient route from a starting point to a destination by evaluating various paths and their associated costs (such as distance or time).

In contrast, the other algorithms mentioned are primarily sorting algorithms. Bubble sort, merge sort, and insertion sort are focused on arranging data in a specific order rather than finding optimal paths or routes. While sorting algorithms are essential in many computing tasks, they don't have direct applications in travel or route optimization like Dijkstra's algorithm does. This distinction clearly illustrates why Dijkstra's algorithm is the correct answer to the question about algorithms used in travel.