MCQS | Which among the following is not true with respect to concatenation of strings in Swift?

Question:Which among the following is not true with respect to concatenation of strings in Swift?

1.Concatenate strings with the + operator to produce a new string

2.Can append a single character to a mutable String

3.Can append multiple characters to a mutable String

4.concatenation of strings is possible using += only not by using append method.