If the personal income tax rate is lowered from 42% to 32%, what is the differential savings for a tax payer having an annual income before tax to the tune of $42400? Pick.
A) $ 3500
B) $ 5000
C) $ 4240
D) $ 7000
E) $ 10000

Rationale: "saving = ( 42 - 32 ) % of 42400 = 4240 . answer : c"
Answer: C