The correct option is C
It would take him 9 months to save $165
Explanation:Josh's savings are:
1, 3, 6, 10, ...
If he continues in this pattern, he would have:
1, 3, 6, 10, 15, 21, 28, 36, 45
Summing these give 165
Therefore, it would take him 9 months to save $165