Given the following code, which statement is correct?

string s$1$;

cin $>>$ s$1$;

Group of answer choices

$"$s$1"$ is variable of "cin" type

$"$s$1"$ is a namespacce

"cin" is an instance of $"$s$1"$ type

$"$s$1"$ is the identifier of a variable

"cin" is a vriable of string type