Brian and Danny are civil partners. They were both born in 1974 and they both claim the basic personal allowance for 2017 -18. Brian's total income for 201 7-18 is £25,000 and Danny's total income for the year is £4,000. None of their income is derived from savings or dividends.

(a) Calculate their income tax liabilities if Danny does not make an election to transfer part of his personal allowance to Brian.

(b) Calculate their income tax liabilities if Danny does make the election.

(c) How would the situation change if Brian's total income were £50,000?