Concept:A line that connects places with the same salinity level is called an isohaline.Explanation:In geography, lines drawn on maps are used to join points of equal value.When the value is salinity, which is the amount of dissolved salt in water, the line is specifically named an isohaline.The other options do not refer to salinity: isopleth is a general term, isopach relates to rock thickness, and isobath relates to water depth.Answer:D. isohaline