What is the output of the following Java program?
import java.util.*;
public class Main {
public static void main(String[] args) {
Map<String, Integer> m = new HashMap<>();
m.put("a", 1); m.put("b", 2); m.put("a", 3);
System.out.println(m.size() + " " + m.get("a"));
}
}- A3 1
- B3 3
- C2 1
- D2 3
Correct answer: D