Jasmine Dimm Is a Call Centre Manager for Tostra, a Mobile

Jasmine Dimm is a call centre manager for Tostra, a mobile phone company. Call centre operators at her call centre are responsible for answering calls from Tostra customers. Some calls are very short, relating to simple enquiries. However, a majority of calls tend to be longer, coming from irate customers complaining about Tostra's services. In these calls, customers are often very emotional and sometimes even abusive. Call operators have no control over what types of calls they get.
Jasmine has developed a new incentive system for her call centre staff. Under the new system, call centre operators are rewarded if they achieve two performance targets: (1) the duration of 90 per cent of the calls is less than 4 minutes and (2) 80 per cent of customers rate Tostra's 'customer service quality' as 'excellent'. Achieving these two monthly performance targets will result in a bonus worth 20 per cent of the call operator's monthly salary.
Based on expectancy theory, the major limitation(s) of Jasmine's reward system is:

A) the incentive system lacks valence and instrumentality.
B) the incentive system lacks expectancy.
C) the incentive system lacks instrumentality.
D) the incentive system lacks expectancy and instrumentality.