According to the web search results, the most critical finding of an application security and DevOps audit would be that the application architecture and configurations did not consider security measures. This finding indicates a serious lack of security by design and security by default principles, which are essential for ensuring the confidentiality, integrity, and availability of the application and its data . If the application architecture and configurations are not secure, they could expose the application to various threats and vulnerabilities, such as unauthorized access, data breaches, denial-of-service attacks, injection attacks, cross-site scripting attacks, and others . This finding could also result in non-compliance with relevant security standards and regulations, such as ISO 27001, PCI DSS, GDPR, and others . Therefore, this finding should be addressed with high priority and urgency by implementing appropriate security measures and controls in the application architecture and configurations.
The other options are not as critical as option B. Option A is a moderate finding that indicates a lack of awareness and assessment of the global security standards specific to cloud, such as ISO 27017, ISO 27018, CSA CCM, NIST SP 800-53, and others . This finding could affect the security and compliance of the cloud services used by the application, but it does not directly impact the application itself. Option C is a severe finding that indicates a major incident that occurred at the cloud service provider level, such as a service interruption, breach, or loss of stored data. This finding could affect the availability, confidentiality, and integrity of the application and its data, but it is not caused by the application itself. Option D is a minor finding that indicates a lack of efficiency and consistency in integrating cloud compliance with regulatory requirements. This finding could affect the compliance posture of the application and its data, but it does not directly impact the security or functionality of the application. Reference:
[Application Security Best Practices - OWASP]
[DevSecOps: What It Is and How to Get Started - ISACA]
[Cloud Security Standards: What to Expect & What to Negotiate - CSA]
[Cloud Computing Security Audit - ISACA]
[Cloud Computing Incident Response - ISACA]
[Cloud Compliance: A Framework for Using Cloud Services While Maintaining Compliance - ISACA]

According to the ISACA Cloud Auditing Knowledge Certificate Study Guide, the cloud customer is the entity that retains accountability for the business outcome of the system or the processes that are supported by the cloud service1. The cloud customer is also responsible for ensuring that the cloud service meets the legal, regulatory, and contractual obligations that apply to the customer's business context1. The cloud customer should also perform due diligence and risk assessment before selecting a cloud service provider, and establish a clear and enforceable contract that defines the roles and responsibilities of both parties1.
The cloud user is the entity that uses the cloud service on behalf of the cloud customer, but it is not necessarily accountable for the compliance of the service1. The cloud service provider is the entity that makes the cloud service available to the cloud customer, but it is not accountable for the compliance of the customer's business context1. The certification authority (CA) is an entity that issues digital certificates to verify the identity or authenticity of other entities, but it is not accountable for the compliance of the cloud service2. Reference:
ISACA Cloud Auditing Knowledge Certificate Study Guide, page 10-11.
Certification authority - Wikipedia

Explanation
The Cloud Security Alliance (CSA) Cloud Controls Matrix (CCM) would be the best information security control framework to implement for a new company that has all its operations in the cloud. The CCM is a cybersecurity control framework for cloud computing that is aligned to the CSA best practices and is considered the de-facto standard for cloud security and privacy. The CCM covers 17 domains and 197 control objectives that address all key aspects of cloud technology, such as data security, identity and access management, encryption and key management, incident response, audit assurance, and compliance. The CCM also maps to other industry-accepted security standards, regulations, and frameworks, such as ISO
27001/27002/27017/27018, NIST SP 800-53, PCI DSS, COBIT, FedRAMP, etc., which can help the company to achieve multiple compliance goals with one framework. The CCM also provides guidance on the shared responsibility model between cloud service providers and cloud customers, and helps to define the organizational relevance of each control12.
References:
Cloud Controls Matrix (CCM) - CSA
Cloud Controls Matrix and CAIQ v4 | CSA - Cloud Security Alliance