hello , hopefully i made this post in the right section lol. im trying to brush up on my automata for a test and i ran into something thats confusing me. this question asks

Which of the following regular expressions denotes the set of all strings over the alphabet {0,1} that contains at least one0.

a) (1+0)*0(1+0)*

b) (1+0)*01*

c) 1*0(1+0)*

d) (1+0)*00*

e) 0*0(1+0)*

f) 1*00*

g) 0

now from what im seeing doesnt everyone of these choices contain atleast 1 zero? i dont know if maybe im reading the question wrong . i understand how to read the * and + but im not quite understanding what its asking. like for a) u can get 0 by itself, so thats atleast 1 zero. for b) u can get 0 alone, thats also atleast 1 zero.