Introduction:
The famous Silk Route was a network of trade routes that connected the East and the West, facilitating the exchange of goods, ideas, and culture between different regions. It played a significant role in promoting economic and cultural exchanges between Central Asia, China, India, and Europe. Several kings and empires controlled different sections of the Silk Route at different times in history.

Explanation:
Among the given options, the king who controlled the famous Silk Route of Central Asia was Kanishka, making option B the correct answer. Kanishka was a powerful ruler of the Kushan Empire, which existed from the 1st to the 3rd century CE. He played a crucial role in expanding and consolidating the empire's territories, which covered parts of present-day Afghanistan, Pakistan, and northern India.

Kanishka's Rule and Control over the Silk Route:
Kanishka's reign marked the peak of the Kushan Empire's power and influence. He was not only a conqueror but also a patron of art, culture, and religion. Kanishka's control over the Silk Route allowed him to establish strong trade connections with various regions, including Central Asia, China, India, and the Roman Empire.

Economic Significance:
Under Kanishka's rule, the Silk Route became a vital artery for the exchange of goods such as silk, spices, precious metals, gems, and other luxury items. The trade routes facilitated the movement of these goods across vast distances, enabling merchants to establish lucrative trade networks and generating significant wealth for the Kushan Empire.

Cultural Exchange:
In addition to economic benefits, the Silk Route also facilitated the exchange of ideas, beliefs, and culture between different civilizations. Kanishka's patronage of Buddhism and his role in hosting the Fourth Buddhist Council in Kashmir further enhanced the cultural exchange between India and Central Asia.

Legacy:
Kanishka's control over the Silk Route and his patronage of art and culture left a lasting impact on the regions connected by the trade routes. The Kushan Empire's influence can be seen in the art and architecture of the time, particularly the Gandhara school of art, which combined Hellenistic and Indian artistic traditions.

Conclusion:
In conclusion, Kanishka, the ruler of the Kushan Empire, controlled the famous Silk Route of Central Asia. His reign marked a period of economic prosperity and cultural exchange, making him an important figure in the history of the Silk Route and its impact on the civilizations connected by it.