Confusion regarding regular language A regular language is a language that can be represented by a regular expression(or for which there exists a DFA), then why is language represented by  0$^{+}$   not regular?

I am asking this because for the following question the correct answer is option 2

Let L denote the languages generated by the grammar S→0S0∣00. 
Which of the following is TRUE?


L=0$^{+}$
L is regular but not 0$^{+}$
L is context free but not regular
L is not context free
The statement (2) is ambiguous. It could mean either
$$
L \text{ is regular but } L \text{ is not equal to } 0^+ \tag{1}
$$
Or it could mean,
$$
L \text{ is regular but } 0^+ \text{ is not regular} \tag{2}
$$
(1) is true and (2) is false.
The authors of the question intended it to mean (1).
But you thought that the meaning was (2), so you were confused.