What causes tendonitis?
o overusing a muscle
o bearing too much weight
o swelling from an injury
o refusing to stretch

Although tendinitis can be caused by a sudden injury, the condition is much more likely to stem from the repetition of a particular movement over time.  SO IT WOULD BE C: SWELLING FROM AN INJURY

Explanation:

waves moving from a fast medium to a slow medium will experience a reflection as light travels more slowly than red light. total internal reflection occurs when the critical angle is.