Rashida's dental insurance coverage includes a co-insurance factor which requires her to pay 30% of the dental costs. The remaining 70% of the costs will be covered by the insurance plan. Which of the following risk management strategies are applied in Rashida's dental insurance costs? 

a.• Risk retention and risk transfer

b.• Risk avoidance and risk transfer 

c.• Risk retention and risk avoidance 

d.• Risk avoidance and risk reduction