Es cuando los electrones no se desplazan fácilmente a través de un material

option a is correct i.e.

explanation:

in context to the membrane of nerve impulse, the outer membrane of neuron is semi permeable that is only sodium ions can pass through the membrane i.e. smaller ions can pass through the membrane while larger ions cannot pass through it.

the limb fractures are among the most common fractures. open fractures are comparatively more dangerous. the injury patterns are dependent on many factors, such as the age of the person, and mechanism of the injury. the closed fractures of the limbs if left untreated may lead to a significant amount of the blood loss, which may be life-threatening for the person. approximately 1000-1500 ml of blood is lost in the close fracture of the femur, and 500-1000 ml of blood is lost in the closed fracture of lower part of the limbs.