Option 1 states that only the Adjutant stork is naturally found in India. To understand this, let`s look at each option individually:

1. The Adjutant stork: This bird species is indeed naturally found in India. It is a large bird with a distinct appearance and is known to inhabit wetlands and estuaries in parts of India.

2. The Emperor penguin: This species is primarily found in Antarctica and its surrounding waters, which is very far from India. Therefore, option 2 is incorrect.

3. The Rattle snake: While India does have various species of venomous snakes, the Rattle snake is not one of them. Rattle snakes are commonly found in the Americas and are not naturally found in India. Therefore, option 3 is also incorrect.

Based on this analysis, option 1 is the correct answer since it correctly states that only the Adjutant stork is naturally found in India.

Note: It`s important to differentiate between species that are naturally found in India versus those that may be found in captivity or have been introduced as non-native species.