Cost Troubles

[parul9]

Although most large public relations firms can afford to run information technology centers in-house, some niche firms are discovering that the cost associated with maintaining an information technology staff and from continuously improving hardware and software are larger than they initially estimated.
A) cost associated with
B) costs associated from
C) costs associated with
D) cost arising from
E) costs arising from

From Platinum GMAT Mock.
The answer is E.
Can someone explain why is can't be C??

[GmatKiss]

Although most large public relations firms can afford to run information technology centers in-house, some niche firms are discovering that the cost associated with maintaining an information technology staff and from continuously improving hardware and software are larger than they initially estimated.
A) cost associated with
B) costs associated from
C) costs associated with
D) cost arising from
E) costs arising from

From Platinum GMAT Mock.
The answer is E.
Can someone explain why is can't be C??

Although most large public relations firms can afford to run information technology centers in-house, some niche firms are discovering that the cost associated with maintaining an information technology staff and from continuously improving hardware and software are larger than they initially estimated.

C) costs associated with
E) costs arising from

E is correct for paralellism