If $y=\left(1+x^{\frac{1}{4}}\right)\left(1+x^{\frac{1}{2}}\right)\left(1-x^{\frac{1}{4}}\right)$, then what is $\frac{d y}{d x}$ equal to?

• A

  $1$
• Correct answer
  B

  $-1$
• C

  $x$
• D

  $x^{\frac{1}{2}}$

Hence, the correct answer is option: 'B'.