Answer:
I agree it would be A) IT is a reactant in a chemical reaction  
Explanation:
a catalyst is a substance that causes a chemical reaction to happen in a different way than it would happen without that catalyst 
 
        
                    
             
        
        
        
Answer:
Fruiting body,  If cut off, will hamper sexual reproduction in fungi.
<u>Explanation:</u>
Fungi are of unicellular, multinucleate, and multicellular. They can be classified based on their reproductive spores and their multinucleate or multicellular filaments nature that can be called as hyphae. The sporocarp  that is also named as fruiting bodyor fruit body is a multicellular structure in which the spore-producing structures, like basidia or asci, are born. 
The fungi consist of spores in the fruiting bodies, that are dispersed for reproduction process. Mushrooms common instance of a fruiting body. These are formed from hyphae, that are smaller threads that usually forms the bulk of fungi. The term mycelium that describes a  hyphae network will be extending in all directions through the soil. Hence, when Fruiting body is cut off it will hamper sexual reproduction in fungi because there are many hyphae with which Fruiting body can be formed.
 
        
             
        
        
        
Answer: B. Take short showers instead of baths.
Explanation:
The water is the most important non-living environmental factor which is the main requirement for survival of every living being. Even though water is a renewable resource which can be replenish by the mode of water cycling in nature but with the increase in the global population the demand of freshwater has increased. Also with the increase in the causes and sources of water pollution the levels of freshwater sources are decreasing. Therefore, the issues of water conservation should be taken into consideration. 
According to the given situation, if an individual needs to conserve water, take short showers instead of baths is the correct option because of the fact that short showers will prevents the wastage of large amount of water which could be wasted while taking baths.