Which of the following is a difficulty associated with environmental protection? a) cost . b) unpredictability . c) sustainability d) all of the above .

The answer is D.

The higher the cost of a particular approach to environmental protection the higher it is a deterrent to use. An example is the use of hydrogen batteries that produce water as a waste product.

Sustainability is the healthy balance in the production and use of a resource. It is usually difficult to find a sustainable environmental protection approach that is also not costly. An example of a sustainable approach is the planting of trees in afforestation and re-afforestation measures.

Due to the unpredictability of weather and climate, engaging long-term approaches to environmental protection can be challenging.

relative dating involves things like higher layers are most recent than rocks lower in the sequence. this can be extended to the known sequence of fossils. rocks containing rabbit fossils are later than those containing dinosaur fossils.  

absolute dating methods mainly use radioactive elements that have known rates of decay and produce recognizable products. for example potassium 40 decays to produce argon. once a rock has solidified the argon is trapped. by measuring the argon and potassium0 you can get an accurate number for the age.  

some other methods are good for archaeological ages. dendrochronology involves recognizing the sequence of tree rings. the orientation of magnetized particles in baked clay can be used to date a fire.

hope this .. .