The correct answer is (C).
According to the first sentence, sequencing the first bacterial genome took 13 months. The second sentence tells us that today it can be done "withiin a few days or even, with the latest equipment, a day." So, tracing DNA sequence is definitely faster nowadays. Is it also cheaper? Yes, the last sentence in the passage notes that "the cost has dropped to about $1,000 per genome, from more than $1 million."
As for the other answers, we know it is not more expensive (Answer A), it is not a longer process (B), and it is definitely possible (Answer D).