Answer:
bill = float(input("Enter the bill amount: "))
rating = int(input("Choose a rating: 1 = Totally satisfied, 2 = Satisfied, 3 = Dissatisfied.: "))
if rating is 1:
    tip = bill * 0.2
elif rating is 2:
    tip = bill * 0.15
elif rating is 3:
    tip = bill * 0.1
print("The rating is: " + str(rating))
print("The tip is: $%.2f" % (tip))
Explanation:
*The code is in Python
- Ask the user for the <em>bill</em> and <em>rating</em>
- Depending on the <em>rating</em>, calculate the <em>tip</em> using <u>if else</u> statement i.e. If the rating is chosen as 1, calculate the tip by taking 20 percent of the bill.
- Print the <em>rating</em> and the <em>tip</em>
 
        
             
        
        
        
well i dont know but i would go with b :D
        
             
        
        
        
Answer:
3.WDM
Explanation:
WDM ( wavelength division multiplexing ) involves signals composed of light beams WDM is used in communication where fibers are used it is used for multiplexing of number of carrier signals  which are made of optical fibers by using different wavelength of laser light it has different wavelength so this WDM is used for signals composed of light beams it has property of multiplexing of signal