Final answer:
Data traffic between Azure services within the same Azure region is generally free, but there may be charges for specific scenarios or services, therefore, users should consult the Azure Pricing page for current details.
Step-by-step explanation:
The question relates to data traffic costs within Microsoft Azure cloud services, particularly within the same region. There can be misconceptions about intra-region data transfer expenses. Generally, data traffic sent between Azure services within the same region does not incur additional costs, making the correct answer (a) Free. However, it's important to note that there are certain instances, such as data egress to external services or data transfer between services that include redundancy across regions, where charges may apply. The pricing for Azure services can also change, so it's best to always refer to the official Azure Pricing page for the most accurate and up-to-date information.