Concept:
Human evolution traces back through several ancestral primates.
• Dryopithecus: Most primitive ape-like ancestor
• Ramapithecus: More advanced than Dryopithecus
• Australopithecus: Early hominid, more human-like
• Neanderthal man: Closely related to modern humans
Step 1: Understand evolutionary sequence.
Dryopithecus $\rightarrow$ Ramapithecus $\rightarrow$ Australopithecus $\rightarrow$ Homo species
Step 2: Identify most primitive.
Dryopithecus is the earliest and most primitive among given options.
Step 3: Analyze options.
• (A) Ramapithecus: More evolved
• (B) Australopithecus: More human-like
• (C) Dryopithecus: Most primitive (correct)
• (D) Neanderthal: Advanced hominid
Step 4: Conclusion.
Thus, Dryopithecus is the most primitive ancestor.
Final Answer: Option (C)