Answer:
A
Step-by-step explanation:
The solution matrices shown are the result of reducing the augmented coefficient matrix to "reduced row-echelon form". Many calculators and spreadsheets have functions specifically for that purpose.
The attachment shows the result of a TI-84 work-alike calculator's reduction of the coefficient matrix. It matches the first choice.
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Additional comment
When the equations are written in the form shown here, with the variables in the same order, and the constant on the right side of the equal sign, the augmented matrix is simply the matrix of the numbers. It is shown as the argument of the RREF function in the attachment.
The left-right order of the variables on the left side of the equal sign matches the top-down order of the solution values in the rightmost column of the reduced matrix. That is, ...
a = 2, b = -2, c = 0.
