Which of the following generate the type of externality previously described? Check all that apply. Susan has planted hundreds of flowers in her front yard, beautifying the neighborhood both for herself and for her neighbors. The city where you live has turned the publicly owned land next to your house into a park, causing trash dropped by park visitors to pile up in your backyard. A leading software company has decided to increase its research budget for inventing new open-source technologies. Your roommate, Eileen, has bought a cat to which you are allergic