If String S1 Has the Value "Computer" and String S2

Multiple Choice

If string s1 has the value "computer" and string s2 has the value "promise", which call to insert will produce the string "compromise"?

A) s1.insert(4, s2, 0, string::npos) ;
B) s1.insert(string::npos, s2, 0, 4) ;
C) s2.insert(0, s1, 0, 3) ;
D) s2.insert(3, s1, 0, 3) ;