$(1)$ If no three points out of four coplanar points are collinear,then a $\ldots \ldots \ldots$ figure formed by joining these four points in order is called a quadrilateral.
$(2)$ $A$ quadrilateral has $\ldots \ldots \ldots$ pairs of opposite sides.

• A
  $1$. closed,$2$. two
• B
  $1$. open,$2$. two
• C
  $1$. closed,$2$. four
• D
  $1$. open,$2$. four