This is another name for the demilitarized zone (DMZ) of a network.
“Three legged firewall” is incorrect. While a DMZ can be implemented on one leg of such a device, this is not the best answer.
“A place to attract hackers” is incorrect. The DMZ is a way to provide limited public access to an organization’s internal resources (DNS, EMAIL, public web, etc) not as an attractant for hackers.
“Bastion host” is incorrect. A bastion host serves as a gateway between trusted and untrusted network.
References: CBK, p. 434 AIO3, pp. 495 -496