Concept:Lines joining places with equal sunshine duration are known as isohels.
Explanation:Maps use special lines to connect places having the same value of a weather element.
Each line type is named according to the element it represents.
Isohels join places that receive equal duration of sunshine or solar radiation.
Isotherms join places with equal temperature.
Isonephs join places with equal cloud cover, not rainfall.
Isohyets join places with equal rainfall or precipitation.
The question asks about the duration of sunshine, so the correct term is isohels.
Answer:A. isohels