Task: Question Answering
Input (English): Question: The folded sheet β: 
 Options:  <1> It is formed by a single polypetide chain. <2> It presents a distance between adjacent amino acids of approximately 4 ångströms. <3> It is formed by the union of two or more strands by hydrogen bonds. <4> Presents the side chains of contiguous amino acids pointing to the same side. <5> They are of two types: parallel, where the chains of the β sheet go in a different direction and antiparallel, where they go in the same direction.
Output (English): 3