Given the task definition and input, reply with output. In this task, you need to provide the correct option for a given problem from the provided options.

Problem: in a group of 60 people , 35 have visited iceland and 23 have visited norway . if 31 people have visited both iceland and norway , how many people have visited neither country ?
Options: a ) 30 , b ) 31 , c ) 32 , d ) 33 , e ) 34
d