28 Some people believe that cloning green giant trees is a key to protecting our environment.
(A) Through modifying the genes of giant trees to make them grow bigger, we can protect the environment.
(B) Through reproducing giant trees, we can solve some environmental problems.
(C) Through cutting branches from giant trees and planting the branches to grow new trees, we can make the environment a better place.
(D) Through transplanting giant trees, we can protect the environment.