Hydrocarbons

The correct answer is A:Fertilization
A copper- is an intrauterine device. It is the most effective form of birth control. It is also the non-hormonal contraceptive device and made up of copper wire. Human fertilization is the union of a human egg and sperm. Copper prevents fertilization as Copper is spermicide in nature due to the presence of copper ion

Since, the energy difference between two conformations of ethane is not so large, so the eclipsed and staggered conformations interconvert rapidly. Thus, it is impossible to isolate these forms at room temperature.