Final answer:
The question asks for the median of the monthly salaries for different grades of U.S. government employees, but there is insufficient data provided to determine the median. The median depends on the distribution of specific values, and we do not have this detailed information.
Step-by-step explanation:
To determine the median of the monthly salaries of U.S. government employees, we must first recognize that the question provides insufficient data to calculate a precise median value. The data provided consists of various ranges and standalone figures, which are not directly relevant to finding the median salary. The median is the middle value in a list of numbers, and without having a clear, ordered list of all individual salaries, we cannot ascertain the median salary.
For this type of question, we typically need a dataset of individual monthly salaries listed from smallest to largest, or at least we need to know the number of salaries and their distribution to locate the median. Given the lack of specifics, it is not possible to select one of the options provided (a: $2,252, b: $1,793, c: $1,903, d: $1,461) as the median monthly salary for different grades of U.S. government employees.