Which of the following is true about insurance policy riders?

A rider is an additional provision that modifies the terms of an original insurance policy. This can include expansions of coverage, exclusions, or other changes to the policy's original terms. Riders give policyholders the flexibility to customize their coverage according to their specific needs or circumstances, thus allowing for adjustments that may be beneficial based on individual situations or risks. This modification aspect of riders is essential, as it can tailor a policy to better suit the insured’s requirements, differentiating it from the base policy.

While some riders may increase coverage and potentially affect premiums, the key feature of a rider is its ability to modify the terms, making option B the most accurate statement about insurance policy riders. Riders can indeed be optional, but this varies among different types of policies, which makes option D not universally applicable. Additionally, riders can influence premium amounts depending on the type of modification they represent; hence, option C is misleading. The misconception that riders can only increase coverage fails to capture their broader role in altering coverage terms.