Based on the provided responses, the most accurate description of the student's mistake would be this option:
"The student did x is less than -4, when the variable is on the other side; -4 is less than x so x is greater than -4."
This option indicates that the student misinterpreted the inequality, switching the inequality sign unintentionally. The other options either misidentify the correctness of the graph or address a different aspect of the inequality.