Read example $10\mathrm{.}4\mathrm{.}6$ traversal examples

Why is A listed last in the postorder traversal?

Question $8$ options:

since A is the root, it is visited first

since A is not the root, it is visited last

since A is the root, it is visited after the right subtree

since A is the root, it is visited last

since A is the root, it is visited after the left subtree

since A is not the root, it is visited first

since A is not the root, it is visited after the right subtree

since A is not the root, it is visited after the left subtree