<em>Answer:</em>
<em>The expression which is does not correct is A. 9 + 12</em>
<em>Step-by-step explanation:</em>
<em>Length of the rectangular garden = 12 feet</em>
<em>Width of the rectangular garden = 9 feet</em>
<em>We need to find the perimeter of the garden.</em>
<em>The perimeter of the garden is given by the formula = 2 × (Length + Width)</em>
<em>⇒ Perimeter = 2 × (12 + 9)</em>
<em> = 2 × 12 + 2 × 9</em>
<em> = 12 + 12 + 9 + 9</em>
<em>So, All the options B. , C, and D. are correct to find the perimeter of the rectangular field.</em>
<em>Therefore, The expression which is does not correct is A. 9 + 12</em>