Which search keywords would you use in the Google search engine to find all the PowerPoint presentations containing information about a target company, ROCHESTON?

One of the steps in information gathering is to run searches on a company using complex
keywords in Google.

Which search keywords would you use in the Google search engine to find all the
PowerPoint presentations containing information about a target company, ROCHESTON?

A.
ROCHESTON fileformat:+ppt

B.
ROCHESTON ppt:filestring

C.
ROCHESTON filetype:ppt

D.
ROCHESTON +ppt:filesearch

Explanation:

Reference:
http://blog.hubspot.com/blog/tabid/6307/bid/1264/12-Quick-Tips-To-SearchGoogle-Like-AnExpert.aspx(specificdocument types)