In NYC, which organization utilizes horses for various purposes?

The NYPD, or the New York City Police Department, employs horses primarily through its Mounted Unit. This unit plays a vital role in maintaining public safety and order, especially in crowded urban areas and during large events like parades and protests. The visibility of mounted officers often helps to deter crime and fosters a sense of security among the public. Additionally, horses are adept at navigating crowds and serve as a valuable asset for crowd control, allowing officers to interact positively with the community.

The other organizations listed have different primary functions. Park Services may use vehicles or other forms of equipment for maintenance and public enjoyment. The Horse Racing Association is focused on the sport and industry of horse racing rather than urban policing. The Department of Transportation is primarily concerned with managing the city's transportation systems and infrastructure, and it does not utilize horses for its operations. Thus, the role of the NYPD’s Mounted Unit is unique and clearly defined, making it the best answer to the question.