Different practice exams expect different answers. My experience is that on my OLD OLD 1900, which only supports 4 vlans, that a switch port can be on as many vlans as you want. On the newer 1912 and 1924 switches, I can not find a way to put a port on more than one vlan.
The truth does not matter, what matters is what Cisco would consider to be a correct answer. Does anybody know?