When diagnosing a starter motor that does not crank, you hear a sharp 'clicking' sound from the starter relay (solenoid) when pressing the start button. What does this suggest?

1. The control circuit and relay coil are working, but the battery voltage is low or the starter motor circuit has high resistance
2. The starter button switch is defective and needs replacement
3. The starter relay solenoid coil is open-circuited and cannot close the contacts
4. The engine ignition fuse is blown, cutting power to the starter button