Consider the following two lines of code. What can you say about $s1$ and $s2?$

String s$1=$ "testing" $+"123"$;

String s$2=$ new String$("$testing $123")$;

s$1$ and s$2$ are both references to the same String object

s$1$ and s$2$ are both references to different String objects

the line declaring s$1$ is legal Java; the line declaring s$2$ will produce a syntax error

s$1$ and s$2$ will compare "equal"

the line declaring s$2$ is legal Java; the line declaring sl will produce a syntax error