Rational character table for $C_2^2$

The row representing the character 4.2.1d is highlighted below.

		1A	2A	2B	2C
	Size	1	1	1	1
	2 P	1A	1A	1A	1A
4.2.1a		$1$	$1$	$1$	$1$
4.2.1b		$1$	$-1$	$-1$	$1$
4.2.1c		$1$	$-1$	$1$	$-1$
4.2.1d		$1$	$1$	$-1$	$-1$