Adjective meaning something has been said with a lot of authority

I'm looking for an adjective qualifying something said with a lot of authority, i.e. that the person saying it is very qualified for or familiar with the subject.

I want use it in a sentence such as "I don't fully understand your answer but [due to its many complicated and technical terms] it seems to be very <insert adjective here>."

How about informed?

I don't fully understand your answer, but it seems to be very informed.

the person saying it is very qualified for or familiar with the subject.

An answer given by such person could be called authoritative:

authoritative - able to be trusted as being accurate or true; reliable : clear, authoritative information and advice | an authoritative source.

New Oxford American Dictionary