Light is a transverse wave and this is what describes light as a wave. The correct option among all the options that are given in the question is the first option. Light is not at all similar to water and sound. It would be a big mistake to consider light as similar to the mediums water and sound. I hope the answer helps.
        
                    
             
        
        
        
The true answer of your question is : 
OH : HYDROXYL GROUP
NH2 : AMINO GROUP
CH3 : METHYL GROUP ( but in rather broader terms, that functional group of formula CnH2n+1 where n is an integer is called ALKYL GROUP where by substituting n by 1,2,3... we obtain methyl for n = 1, ethyl for n = 2, and propyl for n = 3 )
COOH : CARBOXYL GROUP is the correct answer since carbonyl is characterized by the presence of functional group C=O in general the formula of the compound would be 
R-C=O-R’ where R and R’ are alkyl groups like methyl for example. However the carboxyl group could be thought of as a summation of carbonyl + hydroxyl ( CO + OH ) resulting thus in COOH. 
I hope you’ll understand everything, anyway if not i’m always here to help. ♥️
        
             
        
        
        
Gamete Cells. Eggs and sperm are reproductive cells and reproductive cells are called gametes.
        
                    
             
        
        
        
Answer:
2-D
3-D
4-B
5- B
Explanation:
btw also check the answers dont rely on mine