An organization is adopting block chain for a new financial system. Which of the following should be the GREATEST concern for a risk practitioner evaluating the system's production readiness?

A lack of internal expertise in a complex, nascent technology like blockchain significantly increases the risk of misconfiguration, insecure implementation, operational errors, and an inability to effectively monitor, manage, or respond to incidents. This fundamental knowledge gap can severely compromise the system's security and reliability, making it unready for production in a financial context.

While lack of commercial software support is a concern, internal expertise can often compensate, and many blockchain solutions are open source; it's less critical than a complete absence of understanding within the organization.

Varying costs are a business concern for budgeting and financial planning, but they do not directly impact the security or operational readiness of the system in the same fundamental way as a lack of knowledge.

Slow industry adoption is a market or strategic concern, not a direct technical risk factor that impacts the immediate production readiness, security, or stability of the system itself.