Final answer:
Under the Veterans Benefits and Transition Act, Kayce may elect to be treated as a full-year resident of Montana, which is the domicile of their spouse, servicemember Beth.
Therefore, the correct answer is: option 'Montana.
Step-by-step explanation:
Beth, a servicemember, is domiciled in Montana, and her spouse, Kayce, is domiciled in Utah. According to the Veterans Benefits and Transition Act (VBTA), a spouse of a servicemember may elect to adopt the servicemember's state of domicile for tax purposes, which includes being treated as a full-year resident.
Therefore, Kayce may elect to be treated as a full-year resident of Montana, which is Beth’s domicile. This would be true even though they moved to Colorado due to a permanent change of station and later to Maine for the same reason.
The VBTA aims to alleviate the administrative burden on military families who frequently move across state lines due to military orders.