Concept:
The Kushana Empire was one of the most important empires of ancient India and Central Asia. It played a major role in:
• trade between India and the Roman world,
• spread of Buddhism,
• cultural interaction,
• and political integration.
The decline of the Kushanas began during the later phase of the empire, especially from the reign of Vasudeva I.
Step 1: Understanding Assertion (A).
Assertion (A) states:
\[
\text{The Kushana empire started declining from the time of Vasudeva I.}
\]
This statement is historically correct.
Vasudeva I was among the later Kushana rulers. During his reign:
• central political authority weakened,
• territorial control reduced,
• and foreign pressures increased.
Thus, historians generally consider his reign as the beginning phase of Kushana decline.
Step 2: Understanding Reason (R).
Reason (R) states:
\[
\text{The rise of the Sasanians of Iran deprived the Kushanas of their western territories.}
\]
This statement is also correct.
The Sasanians emerged as a powerful dynasty in Iran and:
• challenged Kushana political control,
• captured western territories,
• and weakened Kushana trade and military strength.
This external pressure accelerated the decline of the Kushana Empire.
Step 3: Examining the relationship between Assertion and Reason.
The rise of the Sasanians directly contributed to the weakening of Kushana political authority.
Therefore:
• Assertion (A) is correct,
• Reason (R) is correct,
• and Reason (R) correctly explains Assertion (A).
Hence, the correct option is:
\[
\text{Both (A) and (R) are correct and (R) is the correct explanation of (A)}
\]
Step 4: Historical significance of the Kushana decline.
The decline of the Kushanas led to:
• political fragmentation,
• emergence of regional powers,
• and changes in trade networks.
It also created conditions for the later rise of the Gupta Empire in northern India.
Step 5: Final conclusion.
Since both statements are correct and the Reason properly explains the Assertion, the correct answer is:
\[
\boxed{\text{Both (A) and (R) are correct and (R) is the correct explanation of (A)}}
\]