You have a key-value pair size of l00 bytes. You increase your HFile block size from its default
64k. What results from this change?

A.
scan throughput increases and random-access latency decreases

B.
scan throughput decreases and random-access latency increases

C.
scan throughput decreases and random-access latency decreases

D.
scan throughput increases and random-access latency increases

Explanation:
Larger block size is preferred if files are primarily for sequential access.
Smaller blocks are good for random access, but require more memory to hold the block index, and
may be slower to create
Reference: Could I improve HBase performance by reducing the hdfs block size?