Option A is correct because it will migrate data from one table to another based on the attribute id, which is required when changing the attribute type14. Option D is correct because it will create a data patch that will update 'my.attribute' type from "text" to "int", which is a recommended way of changing the attribute type programmatically4.
To change the type of "my.attribute" from text to int, the Architect should take two steps: A) Migrate data from table "catalog_product_entity_text" to "catalog_product_entity_int" for the attribute_id. This step will move the existing values of the attribute from the text table to the int table, which corresponds to the new type. D) Create a Data Patch and update 'my.attribute' type from "text" to "int". This step will update the attribute metadata in the database and reflect the new type. Option B is incorrect because the Admin panel does not allow changing the type of an existing attribute. Option C is incorrect because writing a plugin for \Magento\Eav\Model\Entity\Attribute\Backend\AbstractBackend::afterLoad() will not change the type of the attribute, but only load data from a different table. Option E is incorrect because running the command bin/magento indexer:reset catalog_product_attribute will not change the type of the attribute, but only reset the indexer status. Reference: https://devdocs.magento.com/guides/v2.4/extension-dev-guide/attributes.html