As we drive an automobile, we dont't think about the chemical consumed and produced. prepare a list of the principal chemicals consumed and produced during the operation of an automobile.

Explanation:

In an internal combustion engine operational in automobiles, fuels are converted into mechanical energy in order to move pistons.

The basic reaction in automobile engines is combustion.

     Principal chemicals consumed                 Chemicals produced

                   Petroleum                                           Carbon dioxide

                                                                               Carbon monoxide

                                                                               Nitrogen oxides

                                                                               Sulfur oxides

  In diesel engines, production of particulate carbon is also produced.

Automobiles such as car, truck, motorbikes run on petrol or diesel. While operating these automobiles, combustion of diesel or petrol takes place which in turn requires oxygen for the process to occur.

Operation of the automobiles consumes oxygen, petrol or diesel and releases harmful chemicals like carbon dioxide (CO2), sulphur dioxide (SO2), carbon monoxide (CO) and many more. These chemicals pollutes the air and also affects the survival of living organisms by affecting the respiratory organs.  

1. the question asks the most appropriate, which seems to rule out "all of the above." your choice appears to be the correct one.

2. the protocol described is good for identifying correlation, but not cause and effect. for cause/effect, you need to devise a protocol that will assign the treatment (or not) to groups that have essentially the same "demographics" with respect to all the other variables. your choice regarding control group seems appropriate. random assignment of treatment (choice d) may be appropriate also. (i think you can argue that b and d are just different descriptions of the same method.)

3. d will randomize the birds, but may not guarantee there are 10 in each group. e will do both, so seems the better choice.

comment on question 2

based on the problem statement, it seems clear that confident, attentive drivers are more likely to use daytime running lights. so, the protocol might need to be devised in such a way that the lights would be turned on or off without the driver's knowledge. (an attentive driver will figure it out.) assigning a confident, attentive driver to a group required to drive without running lights might mess with his/her confidence and attentiveness. you don't want your experiment to do that. (nor do you want the experiment to subject a driver to greater risk of accident as a consequence of driving without running lights.) experiments involving human safety are always problematic.

14 days is the half-life of phosphorus-32