Explanation:
Rajendra Chola I was one of the greatest rulers of the Chola dynasty, which was a powerful maritime and trading empire in South India. He ruled from 1014 to 1044 CE and expanded the Chola Empire to its greatest extent. While options a, b, and d are correct, option c stating that Chola power received a great setback during his reign is not correct.

Rajendra Chola I's Conquests:
Rajendra Chola I was known for his military campaigns and conquests. He undertook several successful expeditions and expanded the Chola Empire to encompass large parts of South India, Sri Lanka, and even territories beyond the Tungabhadra River.

Annexation of Ceylon:
Rajendra Chola I indeed annexed the whole of Ceylon (modern-day Sri Lanka) during his reign. He launched a military campaign against the Sinhalese kingdom and defeated their king, Mahinda V. As a result, he brought Ceylon under Chola control and appointed his own officials to govern the island.

War with Chalukya King Jayasimha II:
Rajendra Chola I also waged war with the Chalukya king Jayasimha II. The Chalukyas were a powerful dynasty in the Deccan region, and Rajendra Chola I sought to expand his empire by conquering their territories. He successfully defeated Jayasimha II and added many Chalukya territories to the Chola Empire.

Expansion North of the Tungabhadra River:
Rajendra Chola I's military campaigns were not limited to the southern regions of India. He also extended his empire north of the Tungabhadra River, which marked the traditional boundary between the southern and northern kingdoms. His conquests included areas like Kalinga (modern-day Odisha) and parts of present-day Andhra Pradesh.

Chola Power and Rajendra Chola I:
Contrary to option c, Rajendra Chola I's reign was marked by significant military successes and territorial expansion. Under his rule, the Chola Empire reached its zenith in terms of power, wealth, and influence. He was a skilled military strategist and administrator, and his conquests solidified the Chola Empire as a dominant force in South India.

In conclusion, the correct answer is option c stating that Chola power received a great setback during Rajendra Chola I's reign is not correct. On the contrary, his reign was characterized by successful military campaigns, territorial expansion, and consolidation of Chola power.