An ideal fluid flows (laminar flow) through a pipe of non-uniform diameter. The maximum and minimum diameters of the pipes are $6.4\mathrm{}\mathrm{c}\mathrm{m}$ and $4.8\mathrm{}\mathrm{c}\mathrm{m}$ , respectively. The ratio of the minimum and the maximum velocities of fluid in this pipe is:

• Correct answer
  A

  $\frac{9}{16}$
• B

  $\frac{\sqrt{3}}{2}$
• C

  $\frac{3}{4}$
• D

  $\frac{81}{256}$

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