Ios device size

Hi,
with unity4 the size of my app was 53 mb inside itunes connect details of compilations. Now is 103.
I read about it and i know that it is for the two architectures but i have some questions.

  1. The size under itunes connect/ detail of compilations is the size that apple checks for the 100MB?
  2. It i build only for arm64, the devices without chip armv64 are receibing the update?
    3.If i build only for armv7 , the dvices with chip armv64 can download the game?
    4.What is the best option of this two?

I can not do nothing for reduce file size because i done in the past and it is all optimized.
Regards and thanks

2. It i build only for arm64, the devices without chip armv64 are receibing the update?
No, if you only build for Arm64 your app will only run on iPhone 6/iPad Air and above

3.If i build only for armv7 , the dvices with chip armv64 can download the game?
Apple will reject your game if you build for only armv7, you must include a 64-bit executable

Is the same with armv7 if it is an update or new app?

Yeah, Apple requires all apps and updates to include 64-bit executables now.

There is a nice description of build size issues that might be helpful here: