Explanation:

There is an error in the Part B of the given sentence. Here we are referring to the automobile sector as one of the most important sectors of the economy in terms of employment generation and job creation at the active and passive levels respectively. A lot of people are employed in this sector in the country. However from the given statement it is not implied correctly. There are many large employers in India and automobile sector is one of them. Therefore, it should have been one of the largest employers. There is no error in any other part of the given sentence.

The correct sentence would have been:

The automobile sector is one of the largest employers in the country, employing about 37 million people, directly and indirectly.

This makes Option B the correct choice among the given options.