In Python: Define, and invoke main, all part A,B,C, are unrelated.

A- Write a program that asks the user for a string and then prints it out in all upper case and then all lower case. Here is a sample run of the program: Please enter a string: Look behind, look here, look ahead You entered (shouting): LOOK BEHIND, LOOK HERE, LOOK AHEAD But better (whispering): look behind, look here, look ahead Hint: You will need to use some functions that operate upon strings Draw a square with dimensions 50 pixels by pixels, centered around the origin: (0,0) and use a for-loop in your solution If t was the turtle that was instantiated, use: to mark the starting point Note trie,") writes the text above the line t write("0,0") Your rendering should look this image to the right. Write a Python program that asks the user to enter a sentence and prints every other character in that sentence. All prompts and format of output must be reproduced. C- A sample run Enter a sentence: I am glad this is a weekend Every othe lett is Ia ldti saveed Hints 1. You will need the 3 argument form of the range function 2. You will need to use the print function with a keyword argument