Which one of the following should IT services deliver to customers?

Value 

It should be Value. Once IT delivers value, IT will deliver the rest.

According to me its "value" because Service is a way of delivering value to customer.

I would vote for "capabilities" as the right answer

Answer is C. Value

Any good IT Service Management Implementation should Deliver the Capabilities, Value with continues improvement for the Operation been serviced by IT. 

Capabilities is the right answer. However, other resources such as people, money, IT infrastructure helps to deliver an IT services to customer.