3. Arduino GPIO Programming

Bob is a space cat who discovered the following circuit with the code. Which buttons does he need to press to turn on the LED?

int button1 = 7;
int button2 = 6;
int button3 = 5;
int ledPin = 3;

void setup() {
  pinMode(button1, INPUT);
  pinMode(button2, INPUT_PULLUP);
  pinMode(button3, INPUT);

  pinMode(ledPin, OUTPUT);
  digitalWrite(ledPin, LOW);
}

void loop() {
  int state1 = digitalRead(button1);
  int state2 = digitalRead(button2);
  int state3 = digitalRead(button3);

  if (state1 == HIGH || state2 == HIGH || state3 == HIGH) {
    digitalWrite(ledPin, HIGH);
  } else {
    digitalWrite(ledPin, LOW);
  }
}