In An Inconvenient Truth, the most likely reason the author uses the heading A Silent Alarm is to

(1 point)
O use an image that all readers can visualize.
show there is a problem that many do not know about.
O to bore the reader.
O frighten readers so they will take action.

The most likely reason the author uses the heading "A Silent Alarm" is to show there is a problem that many do not know about.

The most likely reason the author uses the heading "A Silent Alarm" in "An Inconvenient Truth" is to show there is a problem that many do not know about.

The most likely reason the author uses the heading "A Silent Alarm" in "An Inconvenient Truth" is to show there is a problem that many do not know about. To arrive at this answer, we can analyze the given options and infer the author's intention.

Option 1: "To use an image that all readers can visualize" - This option seems unlikely because the heading itself does not inherently provide a clear visual image. It's more about signaling a problem rather than creating a vivid visualization.

Option 3: "To bore the reader" - This option is unlikely as well since authors generally aim to engage and captivate their readers, not bore them. It would not make sense to use a heading that is designed to be boring.

Option 4: "To frighten readers so they will take action" - This option is also a possibility but is less likely compared to option 2. The heading "A Silent Alarm" is more about raising awareness and signaling a problem rather than explicitly intending to frighten readers. However, it can be argued that the intent is to create a sense of urgency or concern, which could prompt readers to take action.

Considering the above analysis, the most likely reason the author uses the heading "A Silent Alarm" is to show there is a problem that many do not know about, as mentioned in option 2.