Rider period is the period which is offered by the insurer to the policy holder in which the policy would be revived and the benefits pertaining to the policy. In the current scenario, the policy has 20 years of rider policy and is taken when the holder is 40 years old. At the age of 50 years, half of the rider period is consumed and thus the family will wait for the remaining half of the rider period to access the benefits.
Therefore, g's family will receive income for 10 years.