Answer : Option B

Explanation :

The percentage change in the amount invested in raw-materials and in the value of sales of finished goods for different years are:

Percentage change in Amount invested in raw-material:

For 1996 = [  $\frac { (225- 120)} { 12 0}$ x 100 ]% = 87.5%

For 1997 = [ $\frac { (375- 225)} { 225}$ x 100 ]% = 66.67%

For 1998 = [ $\frac { (330- 375)} { 375}$ x 100 ]% = -12%

For 1999 = [ $\frac { (525-330)} { 330}$ x 100 ]% =59.09%

For 2000 = [ $\frac { (420-525)} { 525}$ x 100 ]% =-20%

Percentage change in value of sales of finished goods:

For 1996 = [ $\frac { (300- 200)} { 200 }$ x 100 ]% = 50%

For 1997 =[ $\frac { (500- 300)} { 300 }$ x 100 ]% = 66.7%

For 1998= [ $\frac { (400- 500)} { 500 }$ x 100 ]% = -20%

For 1999 = [$\frac { (600- 400)} { 400 }$ x 100 ]% = 50%

For 2000 =  [$\frac { (460- 600)} { 600 }$ x 100]% = -23.33%

Thus, the percentage difference is same during the year 1997.