Suppose the Government Imposes a Tax of 10 Per Cent

Suppose the government imposes a tax of 10 per cent on the first $40 000 of income and 20 per cent on all incomes above $40 000, what are the tax liability and the marginal tax rate for a person whose income is $30 000?

A) both are 10 per cent
B) 10 per cent and $2000, respectively
C) $3000 and 10 per cent, respectively
D) $3000 and 20 per cent, respectively