3. Port Cpins 0 3 are connected to buttons with external pull-dowii resistors, and pin 4 controls an LED in common-anode configuration. Pins 5, 6, and 7 of Port C are umused. Write a program that turns on the LED when any one of the four buttons is pressed and turns it of otherwise. 4. Write a (brief) modification for 3 so that the LED is turned on only when all four buttons are pressed. 3. Port Cpins 0 3 are connected to buttons with external pull-dowii resistors, and pin 4 controls an LED in common-anode configuration. Pins 5, 6, and 7 of Port C are umused. Write a program that turns on the LED when any one of the four buttons is pressed and turns it of otherwise. 4. Write a (brief) modification for 3 so that the LED is turned on only when all four buttons are pressed