Which of the Following Describes a Characteristic of Fat Use

Which of the following describes a characteristic of fat use during physical activity?

A) Upon commencing an activity, blood fatty acids rise to provide an immediate source of fuel.
B) Fat that is present within the muscle fibre represents the primary source of energy for that muscle.
C) Athletes who consume a high-fat, low-carbohydrate diet for even 1 day are at risk for depleting their glycogen reserves quickly.
D) After consumption of a high-fat diet for at least 2 weeks, physical activities are performed as efficiently as from intake of a high-carbohydrate diet.