Carrying People and Goods over Mountains

To carry people and goods over mountains, there are different modes of transportation available. Let's have a look at them:

1. Aeroplane:
An aeroplane is a fast mode of transportation used for carrying people and goods over long distances. It is the most efficient way to travel across mountains. However, it requires an airport and can be expensive.

2. Submarine:
A submarine is a watercraft that operates underwater. It is not suitable for carrying people and goods over mountains as it is designed for underwater travel.

3. Helicopter:
A helicopter is a versatile mode of transportation used for carrying people and goods over short distances. It can land on uneven surfaces, making it suitable for mountainous terrain. It is relatively expensive but is faster than land travel.

4. All of these:
Out of the three modes of transportation mentioned above, only the helicopter is suitable for carrying people and goods over mountains. Therefore, the correct answer is option 'C' - all of these.

Conclusion:
In conclusion, the most suitable mode of transportation for carrying people and goods over mountains is a helicopter. It can land on uneven surfaces and is faster than land travel. However, if the distance is long, an aeroplane can also be used.