At the beginning of year $1,$ Zach Company purchased a piece of equipment for $$3,900$ with a three $-$ year life and no residual value. Using the straight $-$ line method, what is the adjusting entry for depreciation expense at the end of year $1?$

A$.$ Accumulated Depreciation $-$ Equipment $3,900$

Depreciation Expense $-$ Equipment

B$.$ Accumulated Depreciation $-$ Equipment $1,300$

Depreciation Expense $-$ Equipment $1,300$

C$.$ Depreciation Expense $-$ Equipment $3,900$ Accumulated Depreciation $-$ Equipment $3,900$

D$.$ Depreciation Expense $-$ Equipment $1,300$ Accumulated Depreciation $-$ Equipment $1,300$