3. A firm had $2,800 cash at the beginning of the period. During the period, the firm collected $1,600 in receivables, paid $1,850 to supplier, had credit sales of $4,200, and incurred cash expenses of $2,300. What was the cash balance at the end of the period? A $4,450 B. $250 C. $2,850 D. $1,250