Final answer:
The correct method heading with proper parameter declarations is 'a. public static void guess(double rate, double hours, int deductions);', stating the data types before the variable names.
Step-by-step explanation:
The method heading that uses proper parameter declarations is: a. public static void guess(double rate, double hours, int deductions);
This heading correctly declares the data types for each parameter: 'rate' and 'hours' as double, and 'deductions' as int. Proper syntax in method declarations includes the data type followed by the variable name for each parameter.