For world's largest film industry I tried Bollywood and Mumbai, then gave up. For #1 at IMDB I had no idea if you wanted the number one actor or actress, the highest grossing film, the most "likes"... it would help to have more information for that clue. However, I will chalk it up to my own stupidity that for the most "murine" studio I was trying to think which studio used the most eye drops, and why that would even make sense.
Bollywood/Bombay/Mumbai are simply not correct because the Indian film industry consists of more than this one city. However, I will accept these answers. For the others, I'll try to think of clearer clues (Disney is the least guessed answer, so "murine" might really be too hard.) Thanks for your help!