Answer is B. Hope this helps!
Rocking horse (the others use smaller muscles of the hands), larger muscles like the leg are used to rock.
The first line of defence (or outside defence system) includes physical and chemical barriers that are always ready and prepared to defend the body from infection. These include your skin, tears, mucus, cilia, stomach acid, urine flow, 'friendly' bacteria and white blood cells called neutrophils. Hope this helps.
