The correct option is
A BD=12 inch and
OA=6 inch
Given:
ABCD is a rectangle and
AC=12 inch
Now, as per the given figure,
AC and
BD are diagonals and as we know diagonals of a rectangle are of equal lengths.
∴AC=BD=12 inch
Diagonals of rectangles are bisected at their point of intersection
∴OA=AC2=122=6×22=6 inch
Therefore,
BD=12 inch and
OA=6 inch
(a) is the correct option.