Portability of workloads and data is the correct option.

Portability of workloads and data is most directly tied to vendor lock in because it measures how easily a startup can move applications and data from one cloud provider to another. High portability means fewer technical obstacles to migration and a lower risk of becoming dependent on a single provider, while low portability creates structural barriers that lead to lock in.

Service level agreements are about contractual promises for availability and support and they affect expectations and remedies, but they do not by themselves determine how easy it is to move workloads between providers. That is why Service level agreements is not the best answer.

Interoperability between platforms relates to how well different systems can work together and exchange data, and interoperability can reduce lock in in some cases. However interoperability focuses on interaction rather than the ease of relocating entire workloads and datasets, so it is not as closely tied to the dependency risk as portability.

Difficulty of migrating data and workloads describes a symptom rather than the root factor. Migration difficulty is often the result of poor portability. The question asks which factor is most closely tied to becoming dependent on a single provider, and that root factor is Portability of workloads and data, not the downstream difficulty.

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