Answer:
C: 4
Explanation:
The computation of the payback period is shown below:
Incremental investment in truck 2 is
= $44,000 - $31,000
= $13,000
Now
Year Cash saving in cost Cumulative
1 -$1,000 -$1,000
2 $4,000 $3,000
3 $5,000 $8,000
4 $5,000 $13,000
5 $3,000 $16,000
6 $3,000 $19,000
7 $2,000 $21,000