Pls help-When there isn’t enough oxygen for aerobic respiration, fermentation might occur. There are different types of fermentation. In humans, fermentation occurs when a person is using ATP quickly, and oxygen cannot get to the muscles fast enough. In human muscle cells, fermentation leads to the production of lactic acid. When lactic acid builds up in muscles, it can cause soreness. Other organisms also use fermentation, and sometimes the reactions are very useful to us. When yeast ferments in dough, the carbon dioxide that is released makes the dough rise. Based on the passage, when might fermentation occur?

a. when carbon dioxide is absent

b. when a person is running as fast as she can to catch a bus

c. after a person eats bread

americans began to notice growing differences between the northern and southern sections of the country. there were more people living in cities in the north, which made it more urban. more people lived on farms in the south, which made it more rural. while many people were farmers in the northern states, there were now other ways to make a living, such as working in mechanical cotton gins factories manufacturing cloth, tools and other goods. people in the north supported high tariffs on goods imported from europe because the extra cost encouraged people to “buy american” instead. in the southern states, planters did not like tariffs because they sold most of their production to europe and bought their tools from there as well. southerners believed the protective tariff was something that only northern factory owners keep their profits high. so the southern politicians came up with an idea. they would opt out. they would simply ignore the protective tariff. it was ‘null and void’ in south carolina. the state would not collect the taxes on goods imported into south carolina, no matter what the president said they had to do. this decision led to the nullification crisis.