Eva's computer has been working very slowly. She calls the IT help desk at her office, and they say the computer is likely thrashing, which means that the operating system $\_\_\_\_\_\_.$

a$.$

has not been updated and needs patches and service packs to run

b$.$

has competing resources that are trying to execute at the same time

c$.$

is infected with a virus and cannot access its quarantined files

d$.$

is spending more of its time paging than executing apps