Answer:
Sister chromatids. (Ans. B)
Explanation:
Sister chromatids are defined as the identical chromatids formed by the DNA replication of the chromosome, both copies of chromatids are joint together by a centromere. A pair of chromatids are known as dyad. 
A set of sister chromatids formed during the S phase or synthesis phase of interphase, while all the chromosomes present in a cell is replicated. During the process of mitosis, or second division of meiosis the two sister chromatids are gets separated from each other into two different daughter cells, and each cell receives one copy of the chromosomes.
 
        
                    
             
        
        
        
It would be the pubis bone.
        
                    
             
        
        
        
Answer:
Humans impact the physical environment in many ways: overpopulation, pollution, burning fossil fuels, and deforestation. Changes like these have triggered climate change, soil erosion, poor air quality, and undrinkable water.
Various Human Activities That Affect an Ecosystem
Agriculture. 
Deforestation. 
Overpopulation & Overconsumption. 
Plastic Production. 
Emission of Carbon Dioxide and Other Greenhouse Gases. 
Destruction of the Reefs. 
Production of Black Carbon. 
Draining Streams/Rivers and Destruction of Critical Freshwater Aquifer Recharge Areas (Water Pollution)
Explanation:
Hope this helps!