Which of these is not a potential use for stem cell therapy?

A) help cure Alzheimer's disease

B) bone marrow transplants

C) test new medications

D) all of these are potential uses

The correct answer is option D) "all of these are potential uses".

Explanation:

Stem cell therapy is a promising technology based on stem cells capacity of dividing in practically any cell type in the body. Stem cell therapy can help cure Alzheimer's disease, since it could potentially replace the neuron cells that are lost in this disease. This therapy can help with bone marrow transplants, by synthesizing bone marrow in vitro instead of looking for donors. Stem cell therapy can also help to test new medications, since the tests often require to prove new drugs toxicity, and stem cells can be used for this purpose.

c is having 4 valence electrons and is bonded to three hydrogens and one sulphur atom, therefore, the number of bond pair is equal to four. as all the valence electrons are used in forming the bonds so, there is no lone pair left on carbon.

s is having 6 valence electrons and is bonded to one other sulfur atom and one carbon atom, therefore, the number of bond pair is equal to 2. as only two valence electrons are used in forming the bonds so, four electrons are left. therefore, two lone pairs are present on s.