The correct answer is A. Reconnaissance, map study, preliminary survey and detailed survey.
A reconnaissance survey is a preliminary survey of an area to determine the general features of the area and to select a route for a more detailed survey. A map study is a study of existing maps of the area to determine the location of roads, rivers, and other features that may affect the route of the highway. A preliminary survey is a more detailed survey of the route selected in the reconnaissance survey to determine the exact location of the highway and to identify any potential problems with the route. A detailed survey is a final survey of the route to determine the exact location of the highway and to prepare construction plans.
Option B is incorrect because the preliminary survey should be conducted after the reconnaissance survey. Option C is incorrect because the reconnaissance survey should be conducted before the map study. Option D is incorrect because the map study should be conducted before the preliminary survey.