What is the correct sequence of origin of mammals?
A
Sauropsids $$\rightarrow$$ Pelycosaurs $$\rightarrow$$ Therapsids $$\rightarrow$$ Mammals
B
Synapsids $$\rightarrow$$ Pelycosaurs $$\rightarrow$$ Therapsids $$\rightarrow$$ Mammals
C
Sauropsids $$\rightarrow$$ Synapsids $$\rightarrow$$ Thecodonts $$\rightarrow$$ Mammals
D
Synapsids $$\rightarrow$$ Sauropsids $$\rightarrow$$ Therapsids $$\rightarrow$$ Mammals
Correct option is B. Synapsids $$\rightarrow$$ Pelycosaurs $$\rightarrow$$ Therapsids $$\rightarrow$$ Mammals
Synapsids are primitive reptiles from which originate Pelycosaurs, which are also reptiles. From these, develop more advanced mammal-like reptiles called the Therapsids and then finally develop the Mammals.
So, the correct answer is 'Synapsids → Pelycosaurs → Therapsids → Mammals'.