$\left(x-\frac{1}{x}\right)^{12}$ এর বিস্তৃতিতে মধ্যপদ হবে-

${ }^{-12} C_{6}$

${ }^{12} \mathrm{C}_{6}$

${ }^{12} C_{6} x^{2}$

${ }^{12} \mathrm{C}_{6} \mathrm{x}^{-2}$