I think it's A

Here’s why:

Queueable Apex allows you to handle asynchronous operations. This is important because calling an external system (like the ERP’s REST endpoint) can take time, and you don't want to hold up the creation of the Account record in Salesforce.

By using a Trigger on Account creation, you can ensure the ERP system is called automatically whenever a new Account is created by users in the UC customer onboarding department.

If the call to the ERP system fails, Queueable allows you to manage retries or logging, and the Account creation can still proceed since the process is decoupled from the synchronous flow.

The key requirement here is that the Account must still be created even if the REST call fails. By making the REST call in a Queueable, you ensure that the Account creation process isn’t impacted by the success or failure of the call to the ERP system.