What is the primary characteristic of "big data"?

The correct answer is B: High velocity of data
Let's break down why:
Big data is usually described by the "three Vs" (and sometimes more!): Volume, Velocity, and Variety.
Volume: A large amount of data.
Velocity: Data arriving at a rapid speed.
Variety: Data coming from many different sources and in different formats.
Now let's look at why the other options are not the *primary* characteristic:
Option A: Small volume of data - This is incorrect. Big data, by definition, involves a *large* volume of data.
Option C: Variety of data sources - While variety *is* a characteristic of big data, it's not the *primary* one. The sheer speed at which data arrives is often the biggest challenge.
Option D: Low complexity of data - Big data is actually characterized by *high* complexity, often requiring special tools to process and analyze it.