Which of the following organic compound does not show position as well as functional group isomerism?

Which of the following organic compound does not show position as well as functional group isomerism?

مندرجہ ذیل میں سے کون سا نامیاتی کمپاؤنڈ پوزیشن کے ساتھ ساتھ فنکشنل گروپ آئسومریزم کو بھی نہیں دکھاتا ہے؟
Explanation
Pentanal is an aldehyde, and aldehydes do not show functional group isomerism with other groups.
It also has no other position for –CHO group, so no position isomerism either.