Which statement is true?

Given the code fragment:
class CallerThread implements Callable<String> {
String str;
public CallerThread(String s) {this.str=s;}
public String call() throws Exception {
return str.concat(“Call”);
}
}
and
public static void main (String[] args) throws InterruptedException,
ExecutionException
{
ExecutorService es = Executors.newFixedThreadPool(4); //line n1
Future f1 = es.submit (newCallerThread(“Call”));
String str = f1.get().toString();
System.out.println(str);
}
Which statement is true?

A.
The program prints Call Call and terminates.

B.
The program prints Call Call and does not terminate.

C.
A compilation error occurs at line n1.

D.
An ExecutionException is thrown at run time.