Which of these is a complicated machine?

A. a nail
B. a pencil
C. a spoon
D. a car

A car

Explanation ;

A car runs on multiple complicated objects, that aren’t simply fixed or made by anybody,
a nail wether it’s a nail from the hand or nail to hammer, they’re neither ran as a machine, that wouldn’t be possible-
A pen isn’t a machine but I would understand if you got stuck on that one,
A spoon, in no way shape or form is a complicated machine, or even a regular machine in general.

So your answer is car.