R, a cash basis taxpayer, wanted to defer income from 2021 to 2022. Which of the following will serve that purpose?

	a.	Purchase of a Treasury Bill in November 2021 that matures in February 2022.
	b.	A signed agreement (a deferred compensation agreement) with his employer that the latter will pay him part of his 2021 salary in 2022.
	c.	Delay cashing his last salary check for 2021 until 2022.
	d.	a and b.
	e.	a and c.