Q. How do I cite a survey using MLA?

A survey is not something generally cited. Since you conducted it online, I would suggest 5.6.2b for a work cited online on the Web. Include as much information possible from the basic requirements.

Look here: https://owl.english.purdue.edu/owl/resource/747/08/ for information on thos requirements. An example might be: Smith, John. "School Options Survey." Survey. Name of Web Site. Publisher of Web Site, 29 Nov. 2011. Web. 30 Nov. 2011.