Answer:
$0
Step-by-step explanation:
There is no reason why Carey Company should increase their land account in 2015. As long as the company owns the land they should not modify the land account, since land doesn't depreciate. Even if they build something new on the land site, that will increase the land improvements account or buildings account, not the land account.
If they decide to sell the land then the original purchase value will serve as the basis for calculating capital gains taxes.