Choice "B" is correct. Insuring against losses or entering into joint ventures to address risk is known as risk sharing.
Choice "c" is incorrect. A response to risk that involves the disposal of a business unit, product line or geographical segment is called risk avoidance. Obtaining appropriate insurance is not avoidance.
Choice "d" is incorrect. A response to risk that involves the diversification of product offerings rather than elimination of product offerings is called reduction. Obtaining appropriate insurance is not reduction, it is sharing (the risk has not changed; it has been shifted to another party).
Choice "a" is incorrect. Self insuring or simply tolerating the full exposure to risk is known as acceptance. Obtaining appropriate insurance is not acceptance of risk.