Correct option is (D) 5
Let AB = 4 cm & BC = 3 cm in rectangle ABCD.
Since, all angles are \(90^\circ\) in a rectangle.
i.e., \(\angle A=\angle B=\angle C=\angle D=90^\circ\)
Now, in right angled \(\triangle ABC,\) we have
\(AC^2=AB^2+BC^2\)
\(=4^2+3^2\) = 16+9 = 25 \(=5^2\)
\(\therefore\) AC = 5 cm
Thus, the length of diagonal of rectangle ABCD is 5 cm.