Correct Option (A)
Both A and R are true, and R is the correct explanation of A.
The Kalinga War, fought around 261 BCE, was a pivotal event in Ashoka's reign. Ashoka indeed annexed Kalinga to the Mauryan Empire. This annexation was driven by strategic and economic considerations. Kalinga's geographical location was crucial as it controlled vital land and sea routes connecting northern India with the southern regions and Southeast Asia. These routes facilitated trade and communication, making Kalinga a strategically important territory for the Mauryan Empire to consolidate its power and expand its economic influence. The control over these routes would have provided access to valuable resources and enhanced Mauryan dominance.
Incorrect Options:
Options (B), (C), and (D) are incorrect because both the assertion and the reason are factually accurate, and the reason directly explains the strategic motivation behind Ashoka's annexation of Kalinga. The control over trade routes was a primary factor in the Mauryan expansionist policy towards Kalinga.