Explanation
According to the ServiceNow Hardware Asset Management overview document1, the Content Service is a cloud-based service that provides standardized information for thousands of hardware models1. It helps users to normalize the details of their hardware and consumable models, such as manufacturer, product, model, and device type1.
According to the ServiceNow Product Documentation on Hardware Model Normalization2, the Content Service Setup module allows users to configure the settings for the Content Service, such as the schedule, the frequency, and the scope of the download2.
According to the ServiceNow Knowledge Base article on How to Configure the Content Service Download Schedule3, users can view and modify the number of days until the next Content Service download will occur in the Content Service Setup module3. Users can navigate to Asset Hardware Model Normalization > Content Service Setup and click the Edit button to change the download schedule3.
Therefore, the correct answer is C. Asset Hardware Model Normalization > Content Service Setup.
References:
1: Hardware Asset Management overview - ServiceNow - Now Support
2: Hardware Model Normalization - Product Documentation: Tokyo - ServiceNow
3: How to Configure the Content Service Download Schedule - ServiceNow - Now Support

Explanation
Now Create is a solution that provides step-by-step delivery guidance based on real-world experiences and proven leading practices, to perform digital transformations using ServiceNow products12.
A success pack is a collection of processes and assets that, when executed by qualified ServiceNow practitioners, will deliver successful outcomes for your project13.
A process is a set of tasks that guides you through the implementation or upgrade of a ServiceNow product or feature1.
An asset is an input to the methodology and can be product specific leading practice detailed instructions related to the success pack or other product agnostic project templates and accelerators1.
A success pack can be exported into ServiceNow SPM (and other project execution tools) to accelerate project start-up and provide easy links back to Now Create throughout the project execution1.
The other options are not correct terms used in Now Create. There is no such thing as a Now Create pack, a project pack, a methodology pack, or an asset pack.
References:
1: ServiceNow Create - Now Create
2: Project Methodology - Customer Success - ServiceNow
3: Now Create: Faster implementations, better outcomes - ServiceNow

Stock rules are the rules that define the minimum and maximum quantities of hardware assets in a stockroom1.
Stock rules help to optimize the inventory levels and avoid overstocking or understocking of hardware assets1.
Stock rules have the following purposes:
To automatically transfer assets when a low quantity threshold is detected in a stockroom: This means that when the quantity of a hardware asset in a stockroom falls below the minimum threshold defined by the stock rule, the system automatically creates a transfer order to replenish the stockroom from another stockroom that has excess quantity of the same asset1.
To send notifications when a low quantity threshold is detected in a stockroom: This means that when the quantity of a hardware asset in a stockroom falls below the minimum threshold defined by the stock rule, the system sends an email notification to the stockroom manager or other stakeholders to alert them of the low inventory level1.
Therefore, the purposes of stock rules that are also options in the question are A. To automatically transfer assets when a low quantity threshold is detected in a stockroom and C. To send notifications when a low quantity threshold is detected in a stockroom.
The other options that are not purposes of stock rules are:
To track stock orders from a vendor: This is not a purpose of stock rules, but a function of purchase orders. Purchase orders are the records that capture the details of the vendor contracts for procuring hardware assets2. Purchase orders help to track the status, quantity, and cost of the stock orders from a vendor2.
To track stock movement between stockrooms: This is not a purpose of stock rules, but a function of transfer orders. Transfer orders are the records that track the movement of hardware assets between stockrooms3. Transfer orders help to track the source, destination, quantity, and status of the stock transfers between stockrooms3.
To send notifications when a stock shipment arrives at a stockroom: This is not a purpose of stock rules, but a function of stock order tasks. Stock order tasks are the tasks that track the fulfillment of asset requests from stockrooms4. Stock order tasks help to send notifications when a stock shipment arrives at a stockroom and when the assets are received and verified4. Reference:
1: Stock Rules
2: Purchase Orders
3: Transfer Orders
4: Stock Order Tasks