To limit access to a specific subset of devices within a network, an ACL rule needs to target the appropriate source IP address range while permitting the required traffic. The correct answer specifies the source IP range of 192.168.10.0/24 with a permit action for traffic destined to the file server, which aligns with the administrator's requirements. Other answers involve either denying all traffic, which is too broad, or allowing traffic from incorrect IP ranges, which does not satisfy the requirement of exclusive access for the accounting department.