Final answer:
A Guaranteed renewable policy ensures renewability and stable premium rates, unlike Optionally renewable or Conditionally renewable policies which offer less predictability. The Noncancellable policy provides the highest level of security by preventing both cancellation and rate increases.
Step-by-step explanation:
The type of renewability that guarantees premium rates and renewability is the Guaranteed renewable policy.
Under a Guaranteed renewable policy, the insurer cannot cancel the policy or increase the premium individually, although they may do so for an entire class of policyholders.
This differs from Optionally renewable and Conditionally renewable policies where the insurer has more discretion on whether to renew the policy and at what premium.
Noncancellable policies offer even stronger protections for the insured by guaranteeing that both the coverage cannot be canceled and the premiums cannot be raised as long as the premiums continue to be paid on time.