Final answer:
The incentive value of success (Is) in Atkinson's formula, when the probability of success (Ps) is 0.75, cannot be exactly determined from the given options without additional context about the model being used, but it should likely be less than Ps.
Step-by-step explanation:
In Atkinson's formula, which predicts achievement-related behavior, the relationship between the probability of success (Ps) and the incentive value of success (Is) is typically inverse. This means when Ps is high, indicating a high chance of success, Is is usually lower because the achievement seems less exceptional. Given that Ps = 0.75, the corresponding incentive value of success (Is) is not simply the remainder when subtracted from 1. Instead, it is determined based on the individual's motivation levels and the perceived value of the success. In the options provided, without additional context or a specific formula, it's not possible to determine the exact value of Is. However, reckoning that Is generally decreases as Ps increases, a reasonable assumption might be that Is would not be equal to Ps, but rather less, suggesting either a. 0.25, or b. 0.50 could be potential answers. The exact value cannot be determined without further information about the specific model or formula being used.