What is a time complexity for finding the longest substring that is common in string S1 and S2 (n1 and n2 are the string lengths of strings s1, s2 respectively)?

What is a time complexity for finding the longest substring that is co

1.	What is a time complexity for finding the longest substring that is common in string S1 and S2 (n1 and n2 are the string lengths of strings s1, s2 respectively)?
A.	O (log n!)
B.	(n!)
C.	O (n<sup>2</sup>+ n1)
D.	(n1 + n2)
Answer» E.