In general, blogging reflects "<span>d. the public's newly active role in producing media" since almost all bloggers act independently from their homes. </span>
The answer is D. Sentence 7. When it says "plates may also collide", it is bringing up another topic about the plates. As you read past sentence 7, you notice a shift in topic as you are reading. Instead of plates sliding against each other, the speaker is now talking about them colliding.
Colin Craven<span>'s absolute engrossment in the garden and its creatures fuses him absolutely with the stuff of life
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I'm assuming ringing is the underlined word, so I'd go with A. participle.