The Canvas forms utilized to capture risk assessment and understanding the entity and its environment (UTB procedures) may vary depending on the specific requirements of the auditing firm or organization. However, the options provided do not directly map to any specific auditing standards or forms used in a financial audit context. Therefore, the answer to your question isn't directly applicable to the financial reporting and auditing frameworks mentioned. In a typical audit engagement, risk assessment and understanding the entity and its environment would involve a combination of various procedures, but they wouldn't necessarily correspond to a fixed set of forms like "100-A", "100-B", "102-A", "100-B", "104-A", or "104-B". The forms and methodologies used can be unique to the auditing firm or may follow the auditing standards, such as those issued by the International Auditing and Assurance Standards Board (IAASB) or the American Institute of Certified Public Accountants (AICPA).

In the context of the question, there is no specific canvas form mentioned in the reference text provided. However, if I were to choose the closest match from the options given, it would be:

A. Forms 100-A and 100-B

This choice might represent the initial stages of an audit, where Form 100-A could refer to the initial planning and risk assessment phase, and Form 100-B could indicate the completion of that process. Nonetheless, it's important to note that these forms are not standard across the industry and might be specific to a particular auditing firm's methodology.