A job evaluation that compares salary to external factors is known as:

Comprehensive and Detailed in Depth Explanation:

Job evaluation is the process of determining the relative worth of jobs within an organization to establish fair pay structures. A market-based job evaluation compares the salary of a position to external market data (e.g., industry benchmarks) to ensure competitiveness.

Option A (Ranking): The ranking method involves ordering jobs from highest to lowest value within the organization, not comparing to external factors.

Option B (Pay grade): Pay grades are salary ranges assigned to jobs, not a method of evaluation.

Option C (Market-based): Correct, as this method directly compares salaries to external market rates to determine job value.