What are the two factors upon which the premium of a newly converted plan can be based?

The correct answer is based on the fundamental concepts of insurance underwriting, particularly in relation to life insurance policies. When a plan is converted, the premium is influenced by the attained age of the insured and the original age at which the policy was issued.

Attained age refers to the current age of the policyholder at the time of conversion, which reflects the increased risk to the insurer as the insured ages. As individuals grow older, mortality risk increases, and this higher risk is taken into account when calculating premiums for converted policies.

Original age, on the other hand, represents the age of the insured when the policy was first established. This is relevant because it determines the premium rates that were initially set when the policy was issued. The combination of these two ages ensures that the premium for the converted policy accurately reflects the current risk and the historical context of the policyholder’s health and circumstance at the time of the policy's inception.

The other options do not adequately capture the specific age-related factors that directly influence life insurance premiums during conversions, which is why they are less applicable in this context.