24 feet
Set up a ratio of object height to shadow length.
So x/32=6/8
8(4)=32 so 6(4) would be 24.
Answer:
d
Step-by-step explanation:

First we must apply the Quotient rule that states,

This means that our derivative becomes,

Now we need to calculate
and 


From here the new equation looks like,

And that is the final result.
Hope this helps.
r3t40