“They are planning on attending the convention next month, and so I am.” What is incorrect in this sentence?

Choose the correct sentence.

Choose the correct option to replace the quotation part of each sentence. Often visible as smog, 'ozone is formed in the atmosphere from' hydrocarbons and nitrogen oxides, two major pollutants emitted by automobiles, react with sunlight.

Choose the correct sentence -

Which of the following sentences is correct?