hey, I'm not sure about this answer, but I think it's true, sorry
m(2g+5mk)
Its proportional.
(I need 20 characters but thats all really.)
Let's take a peek of each term, to be specific, the exponent of the variables only, to see what degree each term is

so...which term has the highest degree? well, that one, is the degree of the polynomial
18 is 90% of 20
That is the correct answer :)