Which are primary sources? Three options

Military services record

Textbook written by a historian

Letter written by a soldier in the front line

Documentary about the live is the soldiers in the front line

Recording an interviewer with a veteran who fought un a war

What is the evidence that depression can be linked to genetic as well as environmental factors? a. all individuals in similar stressful environments do not experience depression. b. all individuals with the gene variation tied to depression do not experience depression. c. individuals with a combination of environmental stress and gene variation are more likely to experience depression d. all of the above select the best answer from the choices provided оа 0 0 0