Glenda, a calendar year and cash basis taxpayer, rents property from Janice. As part of the rental

Question:

Glenda, a calendar year and cash basis taxpayer, rents property from Janice. As part of the rental agreement, Glenda pays $8,400 rent on April 1, 2015 for the 12 months ending March 31, 2016.
a. How much is Glenda's deduction for rent expense in 2015?
b. Assume the same facts, except that the $8,400 is for 24 months rent ending March 31, 2017. How much is Glenda's deduction for rent expense in 2015?