Final answer:
An Azure Storage account can contain up to 5 PB or 2 PB of data depending on the region and replication method used, and the number of files can go into the billions, constrained by the total storage capacity. None of the given options are correct.
Step-by-step explanation:
The Azure Storage account limits are determined by the type of storage account you are using. As per Microsoft's documentation, a standard Azure Storage account has the capacity to store up to 5 PB for US regions and 2 PB for all other regions when using the General Purpose v2 (GPv2) accounts, provided that the storage account is using LRS or ZRS replication. The number of files is dependent on the service within the account. For instance, an Azure File Share within a standard storage account can store up to 100 TB of data and the number of files can go into the billions because it is constrained by the total storage capacity rather than a set file count limit.
Therefore, none of the options a) 1 TB, 500 million files, b) 2 TB, 1 million files, c) 5 TB, 2 million files, or d) 3 TB, 1.5 million files accurately reflect the current capacity limitations of an Azure Storage account. It's also important to mention that the capability of storage accounts continues to grow, and for the most precise and updated information, checking the latest Azure documentation is recommended.