Final answer:
An Azure subscription is a logical unit that contains Azure services, resources, and billing. Users can have multiple subscriptions, and a subscription is required to use Azure services.
Step-by-step explanation:
Among the given statements about an Azure subscription, the true statement is that an Azure subscription is a logical unit of Azure services. When using Microsoft Azure, a subscription acts as a container for billing, resources, and services. It is possible for users to have multiple subscriptions under a single account, which allows for greater flexibility in managing costs and resources. Additionally, to access Azure services, one must indeed have a subscription, contradicting the claim that using Azure does not require a subscription.