Answer:
A). Sources that reference only general baseball history and exclude semi-professional.
Explanation:
The selection or use of search terms play a vital role in determining or restricting the search results displayed by excluding the undesired or unwanted outcomes.
As per the question, option A reflects the most likely results of the given search as the capitalized words 'AND' and 'NOT' reflects the Boolean terminology to restrict the unwanted results(excluding semi-professional) and display only the specific results('sources that reference only general baseball) as filtered by the user. Thus, option A is the correct answer.