Which of the following conditions hold good for a train which crosses the bridge of length l in time t1 and crosses another bridge of length \(\dfrac{l}{2} \) in time t2?1. \(t_2 = \dfrac{t_1}{2}\)2. \(2t_2 > t_1\)3. \(t_2 < \dfrac{t_1}{2}\)4. Speed of train is \(\dfrac{l}{10} \ \text{if} \ t_1 -t_2 = 5\)Select the correct answer using the codes given below:

• A. 1 and 4 only
• B. 2 and 4 only
• C. 1 and 3 only
• D. 2 and 3 only