Failure to understand the distinction between mandatory and optional in relationships might yield designs in which awkward (and unnecessary) temporary rows (entity instances) must be created just to accommodate the creation of required entities.

Participation

Explanation: In database designing ,there are two types of participation named as optional and mandatory relationship participation.The optional participation indicates about not necessary participation in relationship but mandatory participation signifies compulsory participation.    

When there is less clearance and knowledge about the concept of the participation then there are chances of the inconsistency in relationship of database .This also leads to the creation of the rows and other entities on temporary basis.

i think the answer would be a