Task: Question Answering
Input (English): Question: The three-dimensional structure of B-DNA: 
 Options:  <1> It is shorter and wider than the A-DNA. <2> It has around 20pb for each 360º turn of the propeller. <3> It is the most stable structure under physiological conditions. <4> It appears when the DNA is placed in a saline solution. <5> It is a left-handed helix.
Output (English): 3