Which extended BNF rule corresponds to the following syntax diagram?

Question $6$Select one:

A B $($B @$)*$

A $($B @$)*$ B

A $=$ B $|$ @ B

A B $|$ B @

A B $|$ @ B

A $=($B @$)*$ B

A $=$ B $|$ B @

A B $($@ B$)*$

A $=$ B $($B @$)*$

A $=$ B $($@ B$)*$