What lines making around the low pressure

The lines making a circle around the low-pressure area indicates Areas of equal pressure. Log in for more information.

Explanation:

On a weather chart, lines joining places with equal sea-level pressures are called isobars. Charts showing isobars are useful because they identify features such as anticyclones (areas of high pressure) and depressions (areas of low pressure).

i think the answer is a and i hope this ; ))

that would be the steamboat because none of the other things are forms of transportation