Final answer:
Without the specific context of the original question, we cannot definitively choose between the given options (A, B, C, D). However, following the format from the practice test provided, the standard form of a linear equation is Ax + By = C, and a sample equation is y = 3,000x + 500.
Step-by-step explanation:
The student has posted a question that seems to lack the context necessary to solve for standard form equations. However, based on the Practice Test 4 Solutions provided, we see example 4 states that the equation for total cost of attendance (denoted as y) with respect to the number of years enrolled (denoted as x) is y = 3,000(x) + 500. This equation is already in standard linear form, which is Ax + By = C, where A, B, and C are constants.