RODRINI On January 1, 2021, Retina Communications purchased a new piece of equipment for an invoice price of $35,000. It cost Retina $1,500 to install the equipment. In addition, Retina paid $500 to purchase accessories to have the equipment up and running. Retina also pays $1,000 for annual hazard and accidental damage insurance to protect the equipment. Retina pays $1,000 The estimated useful life of the equipment is 5 years and its estimated residual value is $3,500. What is the depreciation expense for 2021 if Retina uses the straight-line method? A $3,500 OB $4,000 O $6,700 D.$6,900