Which of the following highly uses the concept of an array?

Detailed Solution:

To determine which option highly uses the concept of an array, analyze how closely each concept depends on contiguous memory and index-based access.

A) Binary Search Tree:
BSTs are built using nodes and pointers in a hierarchical structure. They do not primarily depend on contiguous memory or array indexing.

B) Caching:
Caching uses locality concepts and may internally use arrays, buffers, or hash tables. However, caching itself is a broader memory optimization technique, not something fundamentally based on arrays.

C) Spatial Locality:
Arrays store elements in contiguous memory locations. When one element is accessed, nearby elements are likely loaded into cache as well. This directly demonstrates spatial locality, making it the concept most strongly associated with arrays.

D) Scheduling of Processes:
Process scheduling mainly depends on scheduling algorithms and queue management. Even though queues can be implemented using arrays, scheduling itself is not fundamentally array-based.

Hence, the correct answer is: Spatial Locality.