You are creating a Windows application by using the .NET Framework 3.5.
The application retrieves individual product details from a database within the network. The product
details frequently change.
The product details available to the application can be up to one hour old.
The details of a single product can be retrieved multiple times during a single execution of the application.
You need to design a caching strategy that uses the minimum amount of network bandwidth.
What should you do?

A.
Cache all product details in the memory.
Retrieve the product details from the cache.
Refresh the cache every hour.

B.
Cache all product details in the memory.
Retrieve the product details from the cache.
Remove the product details from the cache every hour.

C.
Retrieve the product details from the cache if they are available in the cache.
Retrieve the product details from the database if they are unavailable in the cache. Then, add the product
details to the cache.
Refresh the cache every hour.

D.
Retrieve the product details from the cache if they are available in the cache.
Retrieve the product details from the database if they are unavailable in the cache. Then, add the product
details to the cache by setting an individual time-out for each product details set.
Remove the product details from the cache on time-out.