Which of the following is the correct expanded form for the series below?
O (7+3•1)+(7 +3-2)+(7 +3,3)+(7+34)
O (7+1)+(7+2)+(7 +3)+(7+4)
O (3-1)+(3-2) +(303)+(3-4)+7
O 3+32 +38 +34 +7
