Which of the following pairs of alkenes is an example of position isomers?

• A

  But-1-ene and 2-methylprop-1-ene
• B

  But-1-ene and 2-methylbut-1-ene
• Correct answer
  C

  But-1-ene and but-2-ene
• D

  But-2-ene and 2-methylprop-1-ene

Solution

For position isomer locant number of $\mathrm{FG}|\mathrm{MB}| \mathrm{S} . \mathrm{C}$ must be differ.
Locant of double bond will be differ.

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