Governments provide tax preferences in several different formats. Suppose a preference of up to $$200$ is proposed to assist with purchase of Kindle readers, so that families may easily have cheap and easy access to electronic books sold by Amazon. The preference equals the amount paid for the Kindle, up to a maximum of $$200.$ Which of the following statements about the revenue loss from this provision is accurate?

a$.$ An itemized deduction has the same impact as an adjustment.

b$.$ An adjustment provides the same tax$-$saving effect for individuals in all tax brackets.

c$.$ A credit provides greater relief to high$-$income taxpayers.

d$.$ An itemized deduction brings the least revenue loss.