Choice "B" is correct. Any amount of "alimony" that is dependent on a child reaching the age of 18, will be considered child support (which is not deductible) for tax purposes. Accordingly, only the $7,000 is deductible as alimony.
Choice "a" is incorrect as it includes the amount deemed to be child support.
Choices "d" and "c" are incorrect. The property division is considered to be a property settlement and is not considered to be alimony. Accordingly, neither the basis, fair market value, nor realized gain has any effect on the alimony deduction.