Alex wants to purchase a boat so that he can take his children fishing. A boat manufacturer has informed him that it would be easiest to custom build the boat according to Alex's specifications. He has 6 different options for engines, 3 different options for size, 4 different cabin configurations, and 7 different electronics systems that he can choose from. What is the total number of different configurations that Alex's new boat could have? A. 126 B. 2,016 C. 504 D. 29