The preposition in the sentence is "from." A preposition is a word that shows a relationship between a noun or pronoun and another word in the sentence. In this case, "from" shows the relationship between the months "April" and "October" and the time period "baseball season." To identify the preposition, you can ask yourself "from April to October" - which word is showing the relationship between these two time periods? The answer is "from."
The preposition in the sentence "Baseball season runs from April to October each year." is A. "from".
