Which of the following pairs is correct for trigonometric inter-relationships?

$1. \cos \theta$	$a. \frac{\cos \theta}{\sin \theta}$
$2. \tan \theta$	$b. \frac{1}{\csc \theta}$
$3. \cot \theta$	$c. \frac{1}{\sec \theta}$
$4. \sin \theta$	$d. \frac{1}{\cot \theta}$
	$e. \sin \theta \cdot \cos \theta$

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