The correct option is Site administrator.

Site administrator can add and manage users across the organization and grant access to company applications and billing features. This role controls site level user management and billing settings which matches Alyssa's duties to add a new Jira account and manage billing access.

Jira Software user is incorrect because this role only provides regular product access for using Jira Software and it does not include permissions to manage other users or billing.

Jira administrator is incorrect because that role focuses on product configuration and global settings within Jira rather than organization wide user and billing management. A Jira administrator may manage schemes and permissions but they do not necessarily control billing or product access across the entire site.

Project administrator is incorrect because it grants permissions only at the project level. Project admins can change project settings and manage project roles but they cannot add users across the site or manage billing.

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