Apex managed sharing is suitable for your scenario because:

- It can give the user on the Reviewer__c record read-only access to the Defect__c record, by creating a share record that links the user, the defect, and the access level.
- It can handle dynamic changes in the Reviewer__c records, such as adding or removing users, by updating or deleting the corresponding share records.
- It can leverage the existing security features of Salesforce, such as authentication, authorization, and encryption.

The other options are not correct. View All on Defect__c is a way of giving users full access to all records of a custom object, regardless of their ownership or relationship. Lightning web component is a way of creating custom user interfaces for Salesforce apps, but it does not control data access or sharing. Criteria based sharing is a way of sharing records based on field values, but it does not support lookup fields or related lists.

Therefore, the correct answer to your question is:

Apex managed sharing

https://help.salesforce.com/s/articleView?id=sf.security_sharing_rules_criteria.htm&language=en_US&type=5
https://developer.salesforce.com/docs/atlas.en-us.securityImplGuide.meta/securityImplGuide/security_sharing_rules_criteria.htm
https://help.salesforce.com/s/articleView?id=000382331&type=1
https://help.salesforce.com/s/articleView?language=en_US&id=sf.security_sharing_rule_types.htm&type=5...