If s1 and s2 are references to two strings then which of the following are the correct ways to find whether the contents of the two strings are equal? if(s1 = s2) if(s1 == s2) int c; c = s1.CompareTo(s2); if( strcmp(s1, s2) ) if (s1 is s2)

• 1, 2
• 2, 3
• 4, 5
• 3, 5