StringTokenizer is a class in the java.util library that can divide a String based on some delimiter String (a delimiter is a separator). If the instruction StringTokener st = new StringTokenizer(str, "&&"); is executed, where str is some String, then st divides up str into separate Strings whenever
a. two ampersands or the substring "and" or "AND" is found
b. two blank spaces are found
c. two ampersands are found
d. a blank space is found
e. a single ampersand ("&") is found