Hey, sorry about this, I had no clue people were still viewing this. I made this 5 years ago, so even I don't remember all the correct answers. The "stands" refer to the concept as they exist within the Jojo's Bizarre Adventure universe. Roughly stated, they are physical/ethereal manifestations of a character's will, and they are often seen as sort of "ghost-like" creatures that fight and interact via the character, or "user". It's hard to explain, so TL;DR, its a hyper-specific term from a manga/anime. If you're asking what stands are within the context of this quiz, pretty much everything from part 3 to part 8 can be one of the answers (part 9 wasn't released when I created this, in fact part 8 hadn't finished yet either).
Also, as a general rule, the stands from part 3 are almost all named after either Egyptian Gods or Tarot Cards + a color, i.e. Star Platinum, Thoth, or Heirophant Green. From part 4 onwards, they tend to be named after Western bands, or their albums/songs. For example, the main character's stand of part 4 is named "Crazy Diamond," after the Pink Floyd song "Shine On You Crazy Diamond".