Tobacco mosaic virus is a tubular filament of size:

• A

  $300 \times 10 \mathrm{~nm}$
• B

  $300 \times 5 \mathrm{~nm}$
• Correct answer
  C

  $300 \times 20 \mathrm{~nm}$
• D

  $700 \times 30 \mathrm{~nm}$

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