**Introduction:**
By the mid-18th century, European powers such as the British, French, Dutch, and Portuguese sought to expand their influence and trade in India. However, they faced various obstacles in their attempts to penetrate western and eastern India. The Marathas and Alivardi Khan played significant roles in controlling these regions, limiting the scope for European powers.

**Marathas and Western India:**
- The Marathas were a powerful regional power in western India during the 18th century. They had established a vast empire under the leadership of their influential rulers like Shivaji and later the Peshwas.
- The Marathas had a strong military and political structure, which helped them consolidate their power and influence in western India. They controlled key territories such as Maharashtra, Gujarat, and parts of present-day Madhya Pradesh and Karnataka.
- The Marathas were known for their guerrilla warfare tactics and had a well-organized administration. They were able to resist and repel European advances in their territories.
- The Battle of Panipat in 1761, where the Marathas suffered a significant defeat against Ahmad Shah Durrani, marked a turning point in their decline. However, they still maintained control over western India, limiting the penetration of European powers.

**Alivardi Khan and Eastern India:**
- Alivardi Khan was the Nawab of Bengal and Bihar from 1740 to 1756. He was a competent ruler who successfully consolidated his power and established control over eastern India.
- Alivardi Khan faced threats from European powers such as the British East India Company and the French East India Company, who sought to expand their influence in Bengal.
- He successfully defended his territories against the Marathas, who had attempted to invade Bengal. Alivardi Khan also defeated the forces of the British and the French in various conflicts.
- Alivardi Khan's strong leadership and military capabilities allowed him to maintain strict control over eastern India, preventing European powers from establishing a significant presence in the region.

**Conclusion:**
The Marathas and Alivardi Khan played crucial roles in controlling western and eastern India, respectively, during the mid-18th century. Their strong military capabilities, well-organized administration, and successful resistance against European powers limited the scope for penetration in these regions. European powers faced significant challenges in their attempts to expand their influence, trade, and colonial control in western and eastern India due to the strict control exerted by the Marathas and Alivardi Khan. Thus, option 'C' - The Marathas and Alivardi Khan, respectively, is the correct answer.

The marathas has control over the western part of India particularly the Deccan plateau whereas the eastern part of the subcontinent was under the control of Alivardi khan who was a king under mughals.these two kingdoms stopped the infiltration of Britishers into their territory in the mid 18th century.