Answer:
Multiply the previous value by 3.
Step-by-step explanation:
The correct pattern in the values as the exponents increase is - Multiply the previous value by 3.
We can see, that
is 
And in the next step,
is 
In the next step,
is 
In the last step,
is 
So, at each step, 3 is multiplied to the previous product/value.
Therefore, the correct answer is last option.