Adding or removing a species from n eco systemcan lead to an imbalance ecosystem for the reason that a species might besurviving due to another one or some species might be playing the role of checkand balance for another, removing that species will cause that check andbalance to stop.
A simple hypothetical example is that a lioneats deer, when you remove a lion from that system the number of deer will riseincredibly which will need more vegetation for them, resulting as there will novegetation be left leading to some other effects and the chain continue…
B. produce mucus that protects parts of the digestive organs from the effects of powerful enzymes needed for food digestion
C. secrete buffers in order to keep the pH of the digestive tract close to neutral
D. provide protection against invading bacteria and other disease-causing organisms that enter the digestive tract in food
b. connective
c. pleural
d. muscle
your most reliable answer would be lithosphere