The choice is up to the player but how would the player know his/her options without a prompt?
It is more of a morality selection, do I keep stolen goods, return them to their rightful owner - even though he is not a nice person (player has already met this character and formed an opinion), do I take the "Robin Hood" route and take the ingots (which were smelted by slave labour) and give them to the family(s) of the slaves and how do I share them out?
Each choice will have an impact on the player's standing with each faction, Ingot Owner, Person who buys the ingots and the two slave factions that mine and smelt the ore for the ingots. "Brownie-points" will be awarded/deducted depending on the choice and the consequences of that choice will be seen later in the game. On a technical point if the player opts to give the ingots to the families of the slaves I need to make these actors and give them dialogue - which I have to do anyway seeing as this option is available.
So yes, it is necessary, how many times have I heard gamers say "I don't know what to do now".
Life is like the choice menu, we all have freedom of choice but are regulated by rules and morals and we usually make that choice having a pretty good idea of the consequences.