Explanation:

Azure Blob Storage Lifecycle Management enables you to automatically transition data to cooler storage tiers, archive data, or delete data based on specified conditions related to creation, last modification, or last access time. These policies are defined in a JSON-based rule structure under the rules property.
As per Microsoft Azure Administrator Study Guide and Official Documentation ("Manage the Azure Blob storage lifecycle"), each rule must define:
Actions: What operation to perform (e.g., tierToCool, tierToArchive, delete).
Filters: Which objects (blobs) the rule applies to, typically filtered by container name, prefix, or blob type.
Conditions: When to perform the action, defined by properties such as:
"daysAfterCreationGreaterThan" - Number of days since blob creation.
"daysAfterLastAccessTimeGreaterThan" - Number of days since last read operation (used when last access tracking is enabled).
"daysAfterModificationGreaterThan" - Number of days since last modification (used for update or write operations).
According to the scenario, the requirement is to move blobs that were not updated for 45 days. The "not updated" condition refers to the last modification date, not creation or access date. Therefore, the correct property to use is:
"daysAfterModificationGreaterThan": 45
The blob type must be specified under "filters". Azure Lifecycle Management currently supports lifecycle actions for:
BlockBlob - the primary type for uploaded files.
AppendBlob - supported, but typically used for log data.
PageBlob - not supported for lifecycle tiering (used for virtual machine disks).
Per Microsoft Docs - "Lifecycle management policy definition", lifecycle tiering actions (tierToCool or tierToArchive) only apply to BlockBlob and AppendBlob, with BlockBlob being the standard choice for data that benefits from tier transitions between Hot, Cool, and Archive tiers.
Hence, the correct configuration is:
"tierToCool": {
"daysAfterModificationGreaterThan": 45
}
"blobTypes": [
"BlockBlob"
]
This policy automatically transitions block blobs in container1 to the Cool access tier when they have not been modified for 45 days, optimizing storage cost while retaining availability.