The format of a poster is as follows:
NAME OF ISSUING AUTHORITY
TAGLINE
TITLE/NAME OF THE EVENT (exhibition, workshop, etc.)
SPECIAL ATTRACTIONS
ILLUSTRATION (WITH A CAPTION)
WHEN (date and time) AND WHERE
ENTRY FEES (if any) AND OTHER RELEVANT INFORMATION
CONTACT INFORMATION
Going by this format, the third blank should include special attractions like refreshment, attractive prizes, and entry pass information, that is all other options. Hence, Option C is correct. The rest of the options are individually incorrect.