Choice "A" is correct. A business continuity plan is broader than a disaster recovery plan. It provides for continuation of all areas of the business (e.g. manufacturing operations), not just for recovery of the management information systems. Choice "d" is incorrect. A daily backup might be necessary, but it will not "ensure" a timely recovery.
Choice "c" is incorrect. Network security has nothing to do with recovery from a disaster.
Choice "b" is incorrect. Backup power will be necessary at the alternate processing facility, but it is only a very small part of either a disaster recovery plan or a business continuity plan.