Species of plants and animals that are at risk for disappearing from the planet are considered to be
a. abundant
b. endangered
c. extinct
d. thriving

Species of plants and animals that are at risk for disappearing from the planet are considered to be endangered. It is different from being extinct because extinct are when species cease to exist, they cannot be found or redeemed anymore. While endangered species, there is still a chance of saving the species or also a chance of extinction. The other choices are so opposite because abundance pose no threat to environment unless they are disease causing organisms and thriving species are close to endangered but still abundant.

B) raising the temperature and reducing the volume of the gas.|-/