In this task, you are given a multiple-choice question about healthcare. Answer the question based on your information and classify your answers into '1', '2', '3', and '4'.
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Question: Question: If you want to estimate the effects of an intervention, you will use: 
 Options:  <1> A transversal design. <2> A retrospective design <3> An ecological study. <4> A randomized clinical trial. <5> An observational design with random selection of the participants.

Answer: 4


Question: Question: ADH increases the osmolality of the renal interstitial medium because it increases: 
 Options:  <1> The permeability to urea in the collector tube. <2> The water permeability of the ascending loop of Henle. <3> The flow in the straight vessels. <4> The reabsorption of NaCl in the collecting tubule. <5> The renal excretion of water.

Answer: 1


Question: Question: The color centers or F centers are produced: 
 Options:  <1> Exclusively in crystals that contain fluorine. <2> By heating a crystal in the vapor of an alkali metal. <3> By cooling a crystal in the vapor of an alkali metal. <4> By heating a crystal in the presence of fluorine. <5> By cooling a crystal in the presence of fluorine.

Answer:
2