The given map of India shows certain areas that are responsible for the production of a specific cash crop. To determine which cash crop it is, we need to analyze each option.

Option 1 is "Cotton". Based on the map, it is evident that the marked areas are suitable for cotton production. Cotton requires warm temperatures, a tropical climate, and well-drained soil, which are characteristics of the regions depicted in the map. Therefore, option 1 is a plausible answer.

Option 2 is "Groundnut". There is no visible indication on the map that suggests groundnut production in the marked areas. Therefore, option 2 is not a suitable answer.

Option 3 is "Sugarcane". Similarly, there is no clear representation of sugarcane cultivation on the map. Hence, option 3 is not the correct answer.

Option 4 is "Tobacco". Again, there is no distinct evidence of tobacco farming in the highlighted regions. Thus, option 4 is not a valid choice.

Therefore, after analyzing the options and referring to the given map, we can conclude that the correct answer is option 1, i.e., "Cotton".