The number of electrons in Br- (bromide ion) is option B) 7.
Bromine (Br) has an atomic number of 35, which means it normally has 35 electrons. However, since the bromide ion (Br-) has a negative charge, it has gained one extra electron, bringing the total number of electrons to 35 + 1 = 36.
So, the correct answer is not listed among the options given