Answer:
The common difference of the associated arithmetic sequence is:
Option: A
17
Explanation:
We know that the sequence is said to be arithmetic if each of the sequence is differ by the preceding term by a fix constant which is known as a common difference.
i.e. d is called a common difference of the sequence if

are the nth and (n+1)th term of the sequence then,

Here we have a table of values as:
X Y d
1 4
2 21 21-4=17
3 38 38-21=17
4 55 55-38=17
5 72 72-55=17
Hence, we get that the common difference is: 17