13.If s1 and s2 are strings where si is repeated in s2 only one time at index 0 then after executing the following statement: s1.Remove(s1.IndexOf(s2)) (2 Points) O the length of the result s1=0 All answers are false the length of the result s1=length of old s1 O the length of the result s1=length of old s1-length of s2