On January 1, 2019, Mandarin Company Purchased a New Truck

On January 1, 2019, Mandarin Company purchased a new truck for $29,400. Its estimated useful life is seven years or 200,000 miles. The truck's expected salvage value is $1,400. During 2019, the truck was driven 20,000 miles.
Assuming units-of-production depreciation, 2019 depreciation expense is:

A) $2,940
B) $4,200
C) $2,800
D) $4,000