Task: Question Answering
Input (English): Question: The use of monolithic columns and continuous beds in liquid chromatography is already very common. To this end: 
 Options:  <1> Microporous membranes are used so that the interaction between a solute and the matrix takes place in the final part of the pore. <2> A separation medium is introduced with a greater degree of continuity than the stationary particle phase so that the mobile phase is forced to traverse the large pores of the medium, improving mass transport. <3> Monodisperse particles are used as a stationary phase in order to improve mass transfer. <4> Flexible organic gels are used from microporous polymers in order to decrease the flow rates. <5> Columns filled with small particles of polymerized silica are used.
Output (English): 2