Answer:
C.(1,one-half),(2,one-fourth),(3,one-eight),(4,one-sixteenth)
Step-by-step explanation:
We have to find the set of ordered pair which could be generated by an exponential function.
We know that the range of exponential function is in geometric progression.
When the sequence is geometric then the ratio of consecutive two term is constant.
In first option
Let 


It is not in G.P.
Hence, it is not the set of ordered pairs which could be generated by an exponential function.
In second function




It is not in G.P
Hence, it is not the set of ordered pairs which could be generated by an exponential function.
In III option





It is in G.P
Hence, it is the set of ordered pairs which could be generated by an exponential function.
In IV option




It is not in G.P
Hence, it is not the set of ordered pairs which could be generated by an exponential function.