The answer is letter c. Like most facets of human behavior and reasoning, intelligence is a multifaceted trait that is influenced by both genetic and environmental influences. Intelligence is perplexing to study, in part since it can be well-defined and measured in different ways. Most descriptions of intelligence comprise the capability to learn from understandings and familiarize to altering environments. Features of intelligence comprise the skill to reason, idea, resolve difficulties, think theoretically, and comprehend multifaceted ideas.