A(n) ________ is a reference placed at the bottom of the page

Which of the following statements is false?

a. A set is an unordered collection of unique values. b. Sets may contain only immutable objects, like strings, ints, floats and tu-ples that contain only immutable elements. c. Sets are iterable, so they are sequences and they support indexing and slicing with square brackets, []. d. Dictionaries do not support slicing.

What will be the output of the following program?

import java.util.HashMap; import java.util.Map; public class Program { public static void main(String... args) { Key k1 = new Key(); Key k2 = new Key(); Map map = new HashMap<>(); map.put(k1, "value1"); map.put(k2, "value2"); System.out.println(map.get(k1)); System.out.println(map.get(k2)); } } class Key { public boolean equals(Object o) { return true; } public int hashCode() { return 1; } } a. value2 value2 b. null null c. value1 value2 d. A Runtime Exception will be thrown.