Answer:
Expectancy theory
Explanation:
Expectancy theory states that an employee's performance is an outcome of his expectations of rewards and incentives which would follow such performance.
The theory was proposed by Victor Vroom who stressed that an employee's motivation is the outcome of his assessment that his efficient performance leads to rewards and incentives.
Expectancy refers to the belief that good performance would be rewarded by the management.
In the given case, John expects his good performance will help him earn a promotion, for which he needs to work hard. This is an example of expectancy theory.
