Which phrase describes a population?

Ineed to know why d is the correct answer asap

Aflashlight battery is an example of a) potential energy b) kinetic energy c) thermal energy d) solar energy

Plz genetic engineering can be applied to many fields including medicine and agriculture. which of the following is a medical application of genetic engineering? a. giving crop plants recombinant dna so that they would be resistant to herbicides. b. examining a persons pedigree to determine whether they can carry a gene for a genetic disease. c. analyzing a persons dna to see how closely they are related to another person. d. certain genes into bacteria so that they will produce a needed medicine.