In this task, You are given an open-domain question that can be answered based on factual information. Your task is to provide \*short\* answer (in a few words only) for the given question. The short answer can be one or more entities or it can also be boolean \*yes\* or \*no\*.

[EX Q]: when did trinidad and tobago become an independent nation
[EX A]: 1962

[EX Q]: when was the us public health service founded
[EX A]: 1798

[EX Q]: who constructed the massive defensive wall around constantinople in the early 5th century ce
[EX A]:
Constantine the Great