Task: Question Answering
Input (English): Question: With respect to those known as solubility enhancers in biotechnological drugs we can say: 
 Options:  <1> Which are not necessary given the good solubility of the active ingredients. <2> Which are necessary given the low solubility of the excipients. <3> They are not necessary in proteins, especially in non-glycosylated ones. <4> The use of lysine or arginine is often resorted to as exalting agents. <5> None of the above.
Output (English): 4