Final answer:
The features of the Hadoop Distributed File System (HDFS) are A) High-speed data processing and B) Data replication for fault tolerance.
Step-by-step explanation:
The Hadoop Distributed File System (HDFS) is a highly reliable storage system designed for large-scale data storage and processing. Among its key features, we find Data replication for fault tolerance and High-speed data processing. Data replication is a cornerstone of HDFS, ensuring that data is preserved in the event of a failure. By creating multiple replicas of data blocks and distributing them across different nodes, HDFS guarantees that the system can recover data even if some nodes fail.
Another important feature of HDFS is its ability to facilitate High-speed data processing. HDFS accomplishes this by maintaining a close proximity between the data and computational resources, which minimizes data transfer times and allows for efficient processing of large data sets. However, it is important to note that HDFS does not support complex SQL queries directly - this functionality is typically provided by other tools in the Hadoop ecosystem such as Apache Hive or Apache Drill. The answer is option a and d.