d) Sheep ranchers found a breed that could withstand the harsh climate.
Explanation:
An increase in the flow of free colonists was facilitated by the successful experience of raising merino sheep in Australia. It turned out that the coarse and tough fleece of English sheep becomes tender and thin under the influence of a relatively mild Australian climate. Rumors of the possibility of quick enrichment have brought thousands of people to Australia. From 1821 to 1826, the free population of European descent in Australia increased from 23 thousand to 36 thousand.
