I don't understand the difference between interest cost and interest expense? Thank you and using Walmarts 2017 financial data

http://stock.walmart.com/investors/financial-information/annual-reports-and-proxies/default.aspx

What is Walmarts total (gross) interest cost for fiscal year ending 1/31/2017 including any interest that may have been capitalized on the balance sheet? (Gross interest cost is total interest cost without netting it with interest income (revenue)).

$2,367 million

$2,403 million

$2,080 million

$2,303 million

What is Walmarts (gross) interest expense for fiscal year ending 1/31/2017, without including any interest that may have been capitalized? (Gross interest expense is total interest expense without netting it with interest income (revenue)).

$2,267 million

$2,403 million

$2,044 million

$2,367 million ******ANSWER?