Which of the following programming languages ​​does Spark implement?

Apache Spark's core engine is written primarily in the Scala programming language. Scala is a high-level language that combines object-oriented and functional programming paradigms. It runs on the Java Virtual Machine (JVM), which allows Spark to seamlessly integrate with the vast ecosystem of Java libraries and provides high performance. While Spark offers Application Programming Interfaces (APIs) for other languages like Java, Python, and R, its fundamental implementation is in Scala.

A. C: Spark's core is not implemented in C. C is typically used for lower-level system programming, not for a high-level distributed computing framework like Spark.
B. C++: Similar to C, C++ is not the primary language for Spark's implementation, which is built to leverage the JVM ecosystem.
C. JAVA: Although Spark runs on the Java Virtual Machine (JVM) and provides a Java API, the source code of the core framework is predominantly written in Scala, making Scala the more accurate answer.

1. Zaharia, M., Chowdhury, M., Franklin, M. J., Shenker, S., & Stoica, I. (2012). Spark: Cluster Computing with Working Sets. In Proceedings of the 9th USENIX Conference on Networked Systems Design and Implementation (NSDI'12). USENIX Association, USA, 1-1. Section 3, Paragraph 1 states, "We have implemented Spark in the Scala programming language, which runs on the Java VM."

2. Apache Spark Official Documentation. Spark Overview. The official documentation explicitly states, "Written in Scala, Spark provides APIs in Scala, Java, Python, and R." This can be found in the introductory sections of the documentation on the official Apache Spark project website.

3. University of California, Berkeley, EECS Department. CS 186: Introduction to Database Systems, Lecture 22: Spark. Course materials frequently note that Spark is "Written in Scala, a high-level language for the JVM." This highlights the foundational role of Scala in Spark's architecture.