Question

Which of the following is not true about about argument?
A)an invalid argument is said to be unsound
B)if the premises of an argument contain false proposition it will be declared unsound
C)for an argument to be sound,the premises and conclusion must be true proposition
D)an argument must be valid before Deciding if is
sound or unsound
Given that "all Nigerian are saint. all saint are angels therefore all Nigerian are angels" which of the following is not true?
A)the argument is unsound
B)the argument is not valid
C)both the two premises and conclusion are false preposition
D)the argument is invalid but unsound