W is the point where blood filtration starts in a nephron which makes option A the most appropriate choice.
<h3>What is a Nephron?</h3>
This is defined as the microscopic structural and functional unit of the kidney.
The renal artery carries blood from your heart to your kidneys during which the process of blood filtration starts immediately.
Read more about Nephron here brainly.com/question/242658
 
        
                    
             
        
        
        
Well if you regularly workout a lot from day to day, you are probably fit for your age, depending on what type of lifestyle you live. Some of the following could be, increased muscle capacity, healthier lungs, increased stamina, things in that area. 
 
        
             
        
        
        
Typically between the ages of 9 and 12 or what many consider late prepubest and early puberty
        
             
        
        
        
In adults aged 18–64, physical activity includes leisure time physical activity (for example: walking, dancing, gardening, hiking, swimming), transportation (e.g. walking or cycling), occupational (i.e. work), household chores, play, games, sports or planned exercise, in the context of daily, family, and community activities. In order to improve cardiorespiratory and muscular fitness, bone health, reduce the risk of NCDs and depression:
Adults aged 18–64 should do at least 150 minutes of moderate-intensity aerobic physical activity throughout the week or do at least 75 minutes of vigorous-intensity aerobic physical activity throughout the week or an equivalent combination of moderate- and vigorous-intensity activity.
Aerobic activity should be performed in bouts of at least 10 minutes duration.
For additional health benefits, adults should increase their moderate-intensity aerobic physical activity to 300 minutes per week, or engage in 150 minutes of vigorous-intensity aerobic physical activity per week, or an equivalent combination of moderate- and vigorous-intensity activity.
Muscle-strengthening activities should be done involving major muscle groups on 2 or more days a week.