Correct Option
The correct option is Pressure.
Explanation
In cartography and meteorology, isolines (or contour lines) are used to represent the distribution of specific climatic variables across a geographical area. These lines connect points of equal value, allowing for the visualization of gradients and patterns such as wind speed or temperature distribution.
Analysis of Options
- Temperature is Incorrect: Lines connecting places with equal temperature are called Isotherms.
- Pressure is Correct: Isobars are lines on a map connecting points having the same atmospheric pressure at a given time or on average over a given period. Pressure values are typically reduced to mean sea level to ensure comparability. The spacing of isobars indicates the pressure gradient; closely spaced isobars denote strong winds, while widely spaced isobars indicate light winds.
- Rainfall is Incorrect: Lines connecting places with equal rainfall are called Isohyets.
- Humidity is Incorrect: Lines connecting places with equal relative humidity are known as Isohumes.
Key Takeaway: Isobars map atmospheric pressure; Isotherms map temperature; Isohyets map rainfall; and Isohumes map humidity.