Australian farmers must rely heavily on to cultivate their crops.

the great artesian basin

irrigation

overflowing rivers

rainfall

Australian farmers must rely heavily on overflowing rivers to cultivate their crops.

Explanation:

The Great Artesian Basin that most of Australia's agriculture is dependent on is a closed system and is subject to run out of water in a few more years depending upon how it is managed. There is frequent flooding in Australia during the summer months from November to April. If the water from these overflowing rivers is used by the Australian farmers to cultivate the crops, it would help in the conversation of other water resources and may help in decreasing the severity of the floods.

The correct answer should be brand c.