Problem is related to Situation. Challenge is a type of Situation. Challenge is a type of Objection. 
Board is a synonym of Room. you are likely to find Shelf in/at/on Room. you are likely to find Photograph in/at/on Shelf. Photographer is derived from Photograph. 
Problem <--RelatedTo--> Situation <--IsA-- Challenge --IsA--> Objection 
Board <--Synonym--> Room <--AtLocation-- Shelf <--AtLocation-- Photograph <--DerivedFrom-- Photographer 