Answer:
a). Not a proposition
b). Proposition
Explanation:
A statement or a proposition is defined as a statement which is known to be true or it is known to be false. But a proposition cannot be both false and true.
If the sentence is not known to be true or false then the sentence is not considered to be a proposition or a statement.
a). All dogs go to heaven.
We do not have any idea that whether all dogs go to heaven or not. Since we do not know whether the sentence is true or false, hence it is not a proposition or a statement.
b). Do you have a Nintendo Switch or a PlayStation 5
In this sentence, I can have either a Nintendo Switch or a PlayStation 5. So the sentence can be either true or false. Since we know the sentence is can be either true or can be false, thus it is a proposition.