Dont underestimate arsenal, they are now much better then they used to be and bayern munich is no longer having pep as their coach so things will change. Arsenal might win with a split of hair against bayern munich , we wont know the result because arsenal is quite good in their home game this season
I am pretty sure Bayern will beat Arsenal, you know it is impossible to beat Bayern, Arrsenal has bad luck every year.
if Arsenal defend well against Bayern munich they will propably can make it off because if get some positive results at Allianz Arena they would made it eadier for them in the return but all of that depends on players availability because both teams known for getting injury Crisis and any team can take advantage of that either Arsenal or Bayern but i think this year Arsenal chances are better then before