Which of these sentences from The Lady or the Tiger? by Stockton shows a cause and effect relationship?

In order to find the sentence which shows a cause and effect relationship, we must first understand what a cause-and-effect sentence is. A cause-and-effect sentences tells us about an action that occurred and what resulted because of that action. Therefore, in these sentences we are looking first for an action that makes something else happen (the cause) and the result of that action (the effect). Think of it as what happens when you accidentally knock a cup filled with water off a table. The cause is the action of your arm or hand hitting the cup and the effect, or the result of you hitting the cup, is that the cup falls to the ground and spills water onto the floor.

In the examples from your question above, we can go through each sentence one by one and decide if there are any cause-and-effect relationships in them. The first three sentences are explanatory or descriptive sentences that simply describe a situation or explain the abilities and surroundings of a person. In those sentences, there are no actions that take place, just descriptions. There are also no "sentence connectors" which are words such as "because" "since" "if" and "then" that show cause and effect. Those are words to look for when trying to find a cause-and-effect sentence. We cannot ask the question "what happens if ____?" because there is no action to ask that question about. Therefore, there is no cause and effect in any of these sentences.

If we look at the last sentence on your paper, we can immediately see one of those connector words ("if"), so this could very well be our cause-and-effect sentence, but let's read it through and find the cause and effect to confirm that this is the right answer. The cause in this sentence would be the action that makes something happen. The action is the person opening a door. What happens if they open the door? Out would come a hungry tiger that would spring on him and tear him to pieces as a punishment for his guilt. That is the effect. Therefore, this is our cause-and-effect sentence, which details an action and what happens as a result of that action.