Working with donors or members of nonprofit organizations to gain financial or volunteer support represents which public relations function?

Development

Explanation:

Public relation or the PR are used to build up relation with the customers and enhance their reputation through social media or other forms of media and self generated communications.

Public relation has three stage functions. They are --

The development phase of the public relation is the earliest phase and here the practitioners were concerned to create awareness and build recognition to the organization or the individual employing public relations to gain financial support or volunteer support.

Thus the answer is --

Development