how to derive the specific ip of a host based on a given network address?

the question goes this way:
1 pc is connected to a router with the router’s network address of 192.168.1.158/28.What is then the ip address that should be given to a pc or host?hera are the choices:
192.168.1.143/28
192.168.1.144/28
192.168.1.145/28
192.168.1.160/28

i need a brief explanation please help!

regards,
jeff