Answer:
Option (3) is correct.
is the expression written as the sum of cubes as

Step-by-step explanation:
<u>Sum of cubes</u> : is defined as 
We have to choose a sum of cubes from given expressions,
Consider 
Here
can be written as 
and
can be written as 
Thus, 
Hence,
is the expression written as the sum of cubes as 
Thus, option (3) is correct.