Step 1: Think in terms of brain size:
Brain size grew steadily in the human line. Australopithecus had a small brain of about 450 cc. Homo habilis had about 600 to 700 cc. Homo erectus had about 900 to 1000 cc. Homo sapiens has about 1350 cc.
Step 2: Link size with age:
A larger brain goes with a later stage in this line. So the age order from oldest to youngest follows the same order as the brain size order.
Step 3: Build the sequence:
The sequence is Australopithecus, Homo habilis, Homo erectus, Homo sapiens.
Step 4: Eliminate wrong options:
Options 2 and 3 both place Homo sapiens before Homo erectus or put Australopithecus late. Option 1 puts Homo erectus before Homo habilis. None of these three fits the growth of brain size.
Step 5: Cross-check with tools and sites:
Stone tools support the same order. Simple pebble tools go with the early forms, while the Acheulean hand axe goes with Homo erectus. Fine, varied tools and art go with Homo sapiens. The tool record therefore agrees with the order we built, and it shows why Homo sapiens cannot sit before Homo erectus.
Step 6: Confirm the answer:
Only option 4 follows the sequence from step 3, so it is correct. The small typo in the printed option does not change the meaning.
Final Answer:
The correct order is Australopithecus, Homo habilis, Homo erectus, Homo sapiens, which is option 4.
\[ \boxed{\text{Option 4}} \]