Gibraltar shouldn't be in the list, as it is a (current) British Overseas Territory. If you really wanted to include it, you would also have to include the 13 other British Overseas Territories.
Also rather daft that the quiz does not accept "Saint" for St., since that's what St. means. But to be frank, this quiz entire has some serious negatives, although the idea is decent.
Agreed, this is what I came here to say. China is definitely a country that contains an area (Hong Kong) that used to be part of the British Empire. Also, if you're including Gibraltar, you also have to include the Falkland Islands, Cayman Islands, British Virgin Islands, Bermuda, Anguilla, etc. And if you happen to be updating it, Swaziland is Eswatini now.
Annoying that the only 3 I didn't get were quizmaster errors - Afghanistan - never a colony/territory, just under influence; Ivory Coast, was French, never British; and Gibraltar, not a country and a current BOT - which should only be here if you're going to include the other 13. The Crown Dependencies of Guernsey, Jersey and the Isle of Man merit inclusion more than Gibraltar does.
Please accept Eswatini, it is the new official name for Swaziland.
Also please accept Saint Lucia, Saint Vincent and Saint Kitts as an alternative to st lucia, st vincent and st kitts. Other quizzes also accept "Saint" which is what "st." stands for.
British Honduras was Belize, Honduras was spanish.
Afghanistan was under british influence (foreign affairs) but never british territory.
https://en.wikipedia.org/wiki/File:The_British_Empire_Anachronous.png
Also please accept Saint Lucia, Saint Vincent and Saint Kitts as an alternative to st lucia, st vincent and st kitts. Other quizzes also accept "Saint" which is what "st." stands for.