Let's calculate No of Units as Revenue / Unit price. Per Unit cost as (Revenue - Profit ) / No of Units. Costs Incurred = Revenue - Profit In that way, we calculate the table as follows.
YEAR
UNIT PRICE
REVENUE
UNITS PURCHASED
PROFIT
COSTS INCURRED
COSTS PER UNITS
EFFECTIVE UNIT PRICE
EFFECTIVE COST PRICE
EFFECTIVE PROFIT
2000
10
700
70
0
700
10
8
10
-140
2001
14
1400
100
100
1300
13
12.2
13
-180
2002
12
1200
100
300
900
9
9.6
9
60
2003
12
900
75
150
750
10
9.6
10
-30
2004
11
1100
100
0
1100
11
8.8
11
-220
2005
8
400
50
150
250
5
8
6
100
2006
10
200
20
100
100
5
10
6
80
2007
14
700
50
200
500
10
14
12
100
2008
10
600
60
0
600
10
10
12
-120
2009
10
800
80
400
400
5
10
6
320
2010
15
900
60
300
600
10
15
12
180
Profit before the changes=1700 Profit after the changes= 150 Cumulative change in the profit = 1550 Hence B is the correct answer.