Answer:
option-C
Explanation:
We are given 
graphs -- I , V , VI have same starting point 
it means that it has same initial values
Suppose, we are given exponential function as

Here , 'a' is initial value
we can see that initial value of graph-I is 30
so, all other graphs must also have 30 initial value
so, graphs 
 have same initial value =30
 have same initial value =30
so, option-C.......Answer