According to the GDPR, the right to data portability applies:

The correct answer is that the right to data portability applies when processing was originally based on the user's consent. Under the General Data Protection Regulation (GDPR), data portability is a key right that allows individuals to obtain and reuse their personal data across different services. This right is specifically designed to enhance individuals' control over their personal data.

The rationale behind this right is rooted in the principles of empowerment and agency, allowing individuals to move their data in a way that maximizes their options in the digital ecosystem. This is particularly applicable in situations where consent serves as the legal basis for processing the data. When individuals have given their explicit consent for their data to be handled in a specific manner, they should also be able to obtain that data in a structured, commonly used, and machine-readable format, and transfer it to another service provider if they choose to do so.

In contrast, the other choices do not meet the criteria for the right to data portability, as the right is specifically tied to data processing based on consent or contract. Processing based on public interest, legitimate interests of the controller, or automated means without consent does not inherently afford individuals the same level of agency regarding their data under GDPR provisions for portability.