Chandragupta I assumed the title of

Explanation:

• Chandragupta I was the first king of the Gupta dynasty, who ruled in northern India. His title ‘Maharajadhiraja’ suggests that he was the great king of kings. 
• Rajendra Chola I  often described as Rajendra the Great, also known as Gangaikonda Chola "the bringer of the Ganges".
• The Nashik inscription mentions king Gautamiputra Satakarni as 'Trisamudratoyapitavahana'.
• Pulakeshi was able to successfully defeat Harshavardhan in the battle on the banks of river Narmada, thus earning him the title Dakshinapatheshwara or the Lord of the South.

Final Answer:

Hence correct answer is option A. Maharajadhiraja was a title assumed by Chandragupta I.