Which of the following statements are true? (There are multiple correct answers)

John is a full-time teacher. He has written a book and receives royalties from it. John's mother, Mabel, is age 65 and lives on her Social Security benefits and gifts from her son, John. This year John directed the publisher to make the royalty check payable to Mabel because she needs the money for support. John must include the amount of the royalty check in his gross income.

On January 1, 2015, an accrual basis taxpayer entered into a contract to provide termite inspection service each month for 36 months. The amount received for the contract was $2,400. The taxpayer should report $1,600 of income in 2016.

Revenue Rulings issued by the National Office of the IRS carry the same legal force and effect as Regulations.

A letter ruling applies only to the taxpayer who asks for and obtains a letter ruling.

The constructive receipt doctrine requires that income must be recognized when it is made available to the cash basis taxpayer, although it has not been actually received. The constructive receipt doctrine does not apply to accrual basis taxpayers.