Direct answer
Objectives follow journal display order. Some depend on your choices; follow the active objective in the game.
Result
As you are, no doubt, already well aware, Geralt has always paid particular interest to crowns and the men who wear them. Kings, you see, are always in need of specialists to perform dirty jobs for them. When Geralt heard King Radovid wanted to see him, he surmised this was just such a moment and set off in the hope a profitable witcher contract was in the offing.