The primary risk of not choosing a strong, secure password for your cloud service is that unscrupulous hackers might gain access to your data. Weak passwords can be easily guessed or cracked, making it easier for malicious individuals to infiltrate your account and steal, manipulate, or delete your sensitive information.
While the other options, such as not being able to access your data or accidental deletions, can certainly occur due to various issues (like account lockout or user errors), they are not direct consequences of having a weak password like security breaches are. Hence, the most significant risk is unauthorized access to your data by hackers.