Question

the tarsier has huge eyes for night vision.
the blue - ringed octopus
the blue - ringed octopus moves to the top of its class for its smart use of poison. this sea creature is hard to spot, because it is only about the length of a pencil. it’s one of the most poisonous animals in the world, but it might not even make its own venom!
what makes the blue - ringed octopus hard to see?
the blue - ringed octopus is hidden by its venom.
the blue - ringed octopus is the length of a pencil.
the blue - ringed octopus is at the top of its class.
the blue - ringed octopus is extremely poisonous.

Explanation:

To solve this, we analyze the passage: "The blue - ringed octopus moves to the top of its class for its smart use of poison. This sea creature is hard to spot, because it is only about the length of a pencil. It’s one of the most poisonous animals in the world, but it might not even make its own venom!" and the options. The question is "What makes the blue - ringed octopus hard to see?". We check each option:

• Option 1: "The blue - ringed octopus is hidden by its venom." The passage says it might not make its own venom and there's no info about venom hiding it. Eliminate.
• Option 2: "The blue - ringed octopus is the length of a pencil." The passage states "it is only about the length of a pencil" and "This sea creature is hard to spot" because of its small size (length of a pencil). This explains why it's hard to see.
• Option 3: "The blue - ringed octopus is at the top of its class." This is about its poison use, not why it's hard to see. Eliminate.
• Option 4: "The blue - ringed octopus is extremely poisonous." This is about its toxicity, not visibility. Eliminate.

Answer:

The option "The blue - ringed octopus is the length of a pencil." (the third option from the left, or the option with text "The blue - ringed octopus is the length of a pencil.")