Complete the sentence with the most appropriate word or phrase out of the given options.
The Himalayas are located ____ the northern frontier of India.

along

The most appropriate word to complete the sentence is along.

The other options are not as accurate. Aside suggests that the Himalayas are located to the side of the northern frontier of India, but this is not the case. In suggests that the Himalayas are located inside the northern frontier of India, but this is also not the case. Above suggests that the Himalayas are located higher than the northern frontier of India, but this is also not the case. Along is the best option because it suggests that the Himalayas are located alongside the northern frontier of India.