Which of the following reduce to unity

$\frac{\sin (-A)}{\sin (180+A)}-\frac{\tan ({90}^0+A)}{\cot A}+\frac{\cos A}{\sin ({90}^0+A)}$

$\frac{\sin {24}^0\cos 6^0-\sin 6^0\sin {66}^0}{\sin {21}^0\cos {39}^0-\cos {51}^0\sin {69}^0}$

$\frac{\cos ({90}^0+A)\sec (-A)\tan ({180}^0-A)}{\sec ({360}^0+A)\sin ({180}^0+A)\cot ({90}^0-A)}$

$\frac{\sin ({180}^0+A)}{\tan ({180}^0+A)}.\frac{\cot ({90}^0+A)}{\tan ({90}^0+A)}.\frac{\cos ({360}^0-A)\cos ecA}{\sin (-A)}$