The law of detachment is a set of three sentences, such that:
Sentence 1 is a statement of the form If p, then q
Sentence 2 is a statement of the form p
Sentence 3 is a conclusion of the form q
Let's see which of the options follow the pattern indicated above:
Option A: If an object is a square, it is a parallelogram. The object is a square. The object is a parallelogram. - MATCHES THE ABOVE PATTERN. Hence, is an example of the Law of Detachment.
Option B: If two angles are linear pairs, the angles are supplementary. The two angles are linear pairs. Therefore, the angles are supplementary. - DOES NOT MATCH THE ABOVE PATTERN.
Option C: If it is snowing, the play will be cancelled. If the play is cancelled, the theater will refund the cost of admission. Therefore, if it is snowing, the theater will refund the cost of admission to the play. - DOES NOT MATCH THE ABOVE PATTERN.
Option D: If it is snowing, the play will be cancelled. It is snowing. Therefore, the play is cancelled. - MATCHES THE ABOVE PATTERN. Hence, is an example of the Law of Detachment.
Hence, option A and option D are examples of the Law of Detachment.