Answer:
David's real income did not change
Step-by-step explanation:
Someone's real income can be seen how much money an individual makes after accounting for inflation.
David's real income did not change as a result of inflation.
Although there was an increase in his salary, there was also a corresponding increase in the consumer price index. This means that things got more expensive and the same amount of things he could buy before his salary raise is still equal to the same amount of things he can buy after his salary raise.
Hence, his real income has remained unchanged because of inflation.