Task: Question Answering
Input (English): Question: The particles of recognition of the signal have as function: 
 Options:  <1> Break the signal sequence. <2> Detect cytosolic proteins. <3> Direct the signal sequences to the ribosomes. <4> Link the ribosomes to the endoplasmic reticulum. <5> Join the mRNA to the ribosomes.
Output (English): 4