Answer: D) By decreasing the activation energy of a reaction
A catalyst is a substance that speed up the rate of chemical reaction without affecting the product of the reaction. They only affect the rate of reaction not the yield of reaction.
Catalyst provide an alternative reaction pathway that has lower activation energy than that of uncatalysed reaction. It increases the frequency of collision and because of these greater collision which lowers the activation energy of the reaction.
The only difference is that animals need the raw resources from another source for respiration, while plants usually have the materials for respiration ready as they have produced them in photosynthesis.
The agent that kills bacteria is called bactericidal. Bactericidal agents act directly by destroying the present bacteria. It is also different from bacteriostatic, because bacteriostatic means the inhibition of the spread and growth of bacteria only.
Your BMI (body mass index) is 21.6, which is a normal BMI. So, you are NOT overweight.