Answer:
C. 
Step-by-step explanation:
Let x be the total monthly sales.
We have been given that a salesperson earns a salary of $700 per month plus 2% of the sales. The salesperson want to have a monthly income of at least $1800.
This means that 700 plus 2% of total monthly sales should be greater than or equal to 1800. We can represent this information in an equation as:


Let us solve our inequality to find the monthly sales (x).
Subtract 700 from both sides of our inequality.

Divide both sides of inequality by 0.02.



Therefore, the total monthly sales must be greater than or equal to 55,000 and option C is the correct choice.