Final answer:
To tokenize the string "c = 1 + 2 + 3" into four tokens using StringTokenizer in Java, the correct delimiter is "+=". This will yield four separate strings: "c ", " 1 ", " 2 ", and " 3".
Step-by-step explanation:
The Java segment provided involves using a StringTokenizer to break a string into tokens. The StringTokenizer class in Java is used to divide a string into multiple tokens based on the specified delimiter. For the line "c = 1 + 2 + 3" to have 4 tokens, we need to consider what characters or sequences would separate this line into four distinct parts. If the delimiter is set as "+=" (option a), this would result in the tokens "c ", " 1 ", " 2 ", and " 3". Therefore, the correct answer is a. String delimArg = "+="; which will yield exactly four tokens.