Answer:
b. []
Explanation:
Arrays are represented using [] . When a method returns an array reference, the method header contains an entry of the type <data-type>[].
For example, a method test which returns a reference to integer array and takes no parameters is of the form:
int[] test();
Similarly a method list_chars which takes a String as an argument and returns an array of chars has the form:
char[] list_chars(String s);