Question

1. with sea otters to keep the population of sea urchins in check, kelp forests can flourish. in fact, even two years or less of sea otter presence can reduce the sea urchin threat in a coastal area. without sea otters present, ______ kelp forests run the danger of becoming barren stretches of coastal wasteland known as urchin barrens.

a) nevertheless,
b) however,
c) hence,
d) likewise,

Explanation:

To solve this, we analyze the logical relationship between the two parts of the sentence. The first part says sea otters help kelp forests flourish (by controlling sea urchins). The second part says without sea otters, kelp forests face a danger. This is a cause - effect relationship.

• Option A "nevertheless" and Option B "however" are used to show contrast, which does not fit here as we need to show a result of the absence of sea otters.
• Option D "likewise" is used to show similarity, which is also not appropriate.
• Option C "hence" is used to indicate a conclusion or a result, so it fits the cause - effect relationship in the sentence.

Answer:

C) hence,