The correct answer is option 3: 3 only.

Option 1 states that India has one of the longest navigable inland water networks in the world. This statement is true. India has an extensive network of rivers, canals, and backwaters that make up its inland waterways, which is one of the largest in the world.

Option 2 states that inland waterways presently help in transporting about 25 percent of the total cargo movement. This statement is not mentioned in the question, so it is uncertain whether it is true or false.

Option 3 states that about 111 inland waterways have been declared as National Waterways under the National Waterways Act, 2016. This statement is true. The National Waterways Act, 2016, declared a total of 111 rivers and canals as National Waterways, which are meant for navigation and transportation purposes.

In conclusion, only statement 3 is confirmed to be correct, while the remaining statements are not explicitly mentioned in the question.