To determine the total cost for using 1,200 gallons of water, we can plug the value of \( x = 1200 \) into the cost function \( c = 0.25x + 20 \).
Substituting \( x \):
\[ c = 0.25(1200) + 20 \] \[ c = 300 + 20 \] \[ c = 320 \]
The total cost for using 1,200 gallons of water is $320.
Thus, the point that accurately represents a monthly usage of 1,200 gallons is \( (1200, 320) \).
Among the provided options, this point matches with:
(1,200, 320) (though it appears to be missing in the provided options).
Was this response correct relative to your question or are there other points you would like to verify? If the choice list is exhaustive, please recheck for potential typographical errors or different representations.