In the given question, a statement of Assertion is followed by a statement of Reason. Mark the correct answer. 

Assertion: Strain began to show within the imperial structure following Krishnadeva Raya’s death in 1529.

Reason: His successors were troubled by rebellious nayakas or military chiefs and by 1542 control at the center had shifted to another ruling lineage.

Both the Assertion and the Reason are correct and the Reason is the correct explanation of the Assertion.

Strain began to show within the imperial structure following Krishnadeva Raya’s death in 1529. His successors were troubled by rebellious nayakas or military chiefs. By 1542 control at the centre had shifted to another ruling lineage, that of the Aravidu, which remained in power till the end of the seventeenth century.