The correct answer to this open question is the following.
Although there are no options attached we can say the following.
John and Mary are both Jamaican citizens and do not have an electoral identification card. On election day, John was allowed to vote however Mary was denied.
The following could have happened.
Under the electoral legislation of Jamaica, on election day you first have to locate the place where you need to vote. This is important because, in that specific place, election officials have your registration. In Jamaica, this place is called the polling station or polling place.
This means that previous to the election, you had to be registered in the polling station.
On election day, you have to show your vote ID card to validate your registration. If you don't have it, you can vote if you have previously registered on time and your name appears on the voter's list. If you are not previously registered your name won't appear on the voter's list and you won't be able to vote.
So in this case, John was already registered and appear on the voter's list. He had no ID but could vote because his name was on the list. That was not the case of Mary that was not on the list and could not vote.