Which of the following groups is true for $\square ABCD?$

$1$. $\square ABCD$ is a rhombus.	$a$. $\overline{AC}$ and $\overline{BD}$ bisect each other.
$2$. $\square ABCD$ is a parallelogram.	$b$. $\overline{AC}$ and $\overline{BD}$ bisect each other at right angles.
$3$. $\square ABCD$ is a rectangle.	$c$. $\overline{AC}$ and $\overline{BD}$ are congruent and bisect each other at right angles.
$4$. $\square ABCD$ is a square.	$d$. $\overline{AC}$ and $\overline{BD}$ are congruent and bisect each other.

• A
  $(1-b), (2-c), (3-d), (4-a)$
• B
  $(1-d), (2-a), (3-b), (4-c)$
• C
  $(1-c), (2-d), (3-a), (4-b)$
• D
  $(1-b), (2-a), (3-d), (4-c)$