AND trees

We are required to find the cost and delay of the circuit. The circuit has an AND tree, but the exact form of the tree is not specified. There are many possible forms of an AND tree, and every one has a different cost and delay.
for example:

Can you please make this issue more clear?

The picture of the circuit in the hw is attached (circuit C1).


Your AND tree is wrong. It has a fanout that is greater than 1.
All AND trees with n inputs have n-1 AND gates.