(JAVA) Write a Java definition for a method that does the following, without calling any other method. Validate parameter:

A.

Return the absolute value of the difference between two integer parameters.

B. Take two floating-point parameters, a and b, and return the integer ratio of their sum to their difference.

C. Take a parameter that is a Celsius (Centigrade) temperature; return the corresponding Fahrenheit temperature. Fahrenheit is 32 degrees above 9/5 of Celsius.

D. Accept the (x,y) positions of two opposite corners of a rectangle as parameters and return the area of the rectangle.