Five jumbled up sentences (labelled 1, 2, 3, 4 and 5), related to a topic, are given below. Four of them can be put together to form a coherent paragraph. Identify the odd sentence and key in the number of that sentence as your answer.

The correct option (the odd sentence) is:
"Animals have an interest in fulfilling their basic needs, but also in avoiding suffering, and thus we ought to extend moral consideration."

Step-by-step Explanation:

1. Analyze the themes of the sentences:
Three of the provided sentences focus directly on the philosopher Peter Singer, his landmark 1975 text Animal Liberation, and his specific philosophical arguments. The remaining sentence is a general philosophical assertion about animal interest and moral consideration that does not mention Singer or link to the specific biographical/literary context of the others.

2. Form a coherent paragraph with the connected sentences:
Let us arrange the sentences that focus on Peter Singer to form a logical flow:
• Sentence 1 (Introduction): "The event that publicly announced animal rights as a legitimate issue within contemporary philosophy was Peter Singer’s Animal Liberation text in 1975." (This introduces Peter Singer and his influential book as the starting point).
• Sentence 2 (Elaboration on Singer's framework): "Singer viewed himself as a utilitarian, and presents a direct moral theory concerning animal rights, in contrast to indirect positions, such as welfarist views." (This builds directly on the introduction by detailing Singer's philosophical stance).
• Sentence 3 (Details of Singer's argument): "He argued for extending moral consideration to animals because, similar to humans, animals have certain significant interests." (The pronoun "He" directly refers back to Peter Singer, explaining the core premise of his argument in the book).

3. Identify the odd sentence:
The sentence "Animals have an interest in fulfilling their basic needs, but also in avoiding suffering, and thus we ought to extend moral consideration" is a general statement. Although it shares a thematic overlap with animal ethics, it lacks any structural or narrative connection to the specific discussion of Peter Singer's 1975 publication and his utilitarian theory. Therefore, it is the odd sentence out.