[单项选择]

F: We ought not to test the safety of new drugs on sentient animals, such as dogs and rabbits. Our benefit means their pain, and they are equal to us in the capacity to feel pain.
G: We must carry out such tests; otherwise, we would irresponsibly sacrifice the human lives that could have been saved by the drugs.
Which of the following, if true, is the best objection that could be made from F’s point of view to counter G’s point（）

A. Even though it is not necessary for people to use cosmetics, cosmetics are also being tested on sentient animals
B. Medical science already has at its disposal a great number of drugs and other treatments for serious illnesses
C. It is not possible to obtain scientifically adequate results by testing drugs in the test tube, without making tests on living tissue
D. Some of the drugs to be tested would save human beings from great pain
E. Many tests now performed on sentient animals can be performed equally well on fertilized chicken eggs that are at a very early stage of development

Gene therapy and gene-based drugs are two ways we could benefit from our growing mastery of genetic science. But there will be others as well. Here is one of tile remarkable therapies on the cutting edge of genetic research that could make their way into mainstream medicine in the coming years.
While it’s true that just about every cell in the body has the instructions to make a complete human, most of those instructions are inactivated, and with good reason: the last thing you want for your brain cells is to start churning out stomach acid or your nose to turn into a kidney. The only time cells truly have the potential to turn into any and all body parts is very early in a pregnancy, when so called stem cells haven’t begun to specialize.
Yet this untapped potential could be a terrific boon to medicine. Most diseases involve the death of healthy cells -- brain cells in Alzheimer’s, cardiac cells in heart disease, pancreatic cells in diabetes, to
A. The principle of gene therapy is applicable to that of cloning.
B. The isolation of stem cells is too difficult to be feasible.
C. It is reasonable for all body instructions to be activated.
D. Cloned animals will eventually take control of the world.