Yes, B is correct.
The reason is that in order to compare brother and "I" the two words must be in the same case -- in this instance, they must both be in subject case. The sentence is somewhat truncated. The entire thought would read like this:
"My brother knows more about technology than I do." You wouldn't say "...than me do" right?
http://grammar.ccc.commnet.edu/grammar/cases.htm
18a. My brother knows more about technology than me.
18b. My brother knows more about technology than I.
my answer is B. please explain answer
2 answers
oh, thank you!!