Task: Question Answering
Input (English): Question: In the elderly the total body water: 
 Options:  <1> It is half that in the adult. <2> It decreases fundamentally at the expense of the intravascular compartment. <3> It decreases mainly due to the reduction of extracellular fluid. <4> It decreases greatly as a result of the loss of muscle mass. <5> It represents 30% of body weight.
Output (English): 4