Correct Answer:
B. Drop Box
Drop Box is a widely recognized and famous online cloud storage service. It allows users to store files and folders online, synchronize them across multiple devices, and share them with others.
- Google Space (A) is not a recognized cloud storage service; Google's offering is called Google Drive.
- Google Drive (C) and iCloud (D) are also famous and popular cloud storage services offered by Google and Apple, respectively. However, among the given options, Dropbox stands out as an independent and pioneering service in the cloud storage market, making it a correct answer for a famous service.