Explanation : 'Middle term should be distributed in at least one premise' is the only correct statement among those given.
Categorical syllogisms have exactly three
categorical propositions, two of which are
premises; and the third is the conclusion.
There are exactly three terms, each
appearing only twice.
Four rules apply to all valid categorical
syllogism:
Rule 1: The middle term must be distributed
in at least one premise.
Rule 2: Any term that is distributed in
the conclusion must be distributed in the
premises.
Rule 3: The number of negative premises
must be equal to the number of negative
conclusions.
Rule 4: No particular conclusion can be
drawn from exclusively universal premises.
Arguments that pass each of these tests are
valid. Those that fail to satisfy even one of
the rules are invalid