: one designated b especially as the second in order or class
I chose option b.
5
a
: a grade rating a student's work as good but short of excellent
b
: one graded or rated with a B
a b student
6
: something shaped like the letter B
7
capitalized: the one of the four ABO blood groups characterized by the presence of antigens designated by the letter B and by the presence of antibodies against the antigens present in the A blood group