HOTSPOT
You have a server named Server4 that runs Windows Server 2012 R2. Server4 has the Windows
Deployment Services server role installed.
Server4 is configured as shown in the exhibit. (Click the Exhibit button.)
To answer, complete each statement according to the information presented in the exhibit. Each
correct selection is worth one point.
Answer: 
How about https://technet.microsoft.com/en-us/library/jj648426(v=ws.11).aspx
4.In the Image Properties dialog, on the General tab, enter in your desired priority into the Priority text box. The items that appear first on your install image menu are the ones with the lowest value.
I try it in my test lab.
If you connect WDS form x64 PC? you can choose only x64 boot images.
ALso, boot image with less priority number, appears first.
Alexsander is rigth.
http://serverfault.com/questions/554389/wds-deploying-different-architectures-64-bit-and-32-bit-with-a-single-boot-ima
From https://technet.microsoft.com/en-us/library/cc730907
“The boot menu on x86-based computers will display only x86 boot images (because x86-based computers cannot run x64 boot images); however, if you boot into an x86-based boot image from an x64-based computer, x86-based and x64-based install images will be displayed. If you boot into an x64-based boot image from an x64-based computer, only x64-based boot images will be displayed.”
So, you should be able to use an x86 boot image for both x86 and x64-based hardware.
Answer is correct.
first part of answer is wrong as x64 system can only see x64 boot images.
so the first questions answer is : bootimage1 and bootimage2
second question is correct:bootimage2 as it will show only x64 boot images and lower number (10) is higher priority than 100
tested in testlab
you are right