(a) The following is the food chain that provides food to the lion in the given case:
Plants Deer Man Lion
(b) The lion could have looked for a herbivore, such a wild buffalo or a zebra, if it he had not got the hunter as prey.
(c) Any top consumer, such as a tiger or a python, could have been in the place of the lion in the forest.
(d) In the food chain,
Plants Goat Man
man is the top consumer whereas, in the food chain,
Plants Deer Man Lion,
the top consumer is lion.