Why do some plants perform C4 photosynthetic pathways instead of the more common C3 pathway?

Which of the following is not an example of conflict between related individuals?

Some technological solutions to problems like global warming meet the specific needs and situations of local communities. an example from india involves converting the solid waste from cattle into clean-burning fuel for cooking. this reduces the amount of greenhouse gases, specifically methane and carbon dioxide, released into the environment from wood fires. when evaluating the feasibility of implementing this solution, computer models are used to weigh costs against benefits. what factor is least likely to impact the decision on adopting this technology?

All individuals have two alleles for a given trait. according to mendel's these alleles are passed down one each from both mother and father.