(15)The choice of the method to calculate the best estimate should be proportionate to the nature, scale and complexity of the risks supported by the insurance or reinsurance undertaking. The range of methods to calculate the best estimate includes simulation, deterministic and analytical techniques. For certain life insurance contracts, in particular where they give rise to discretionary benefits depending on investment returns or where they include financial guarantees and contractual options, simulation methods may lead to a more appropriate calculation of the best estimate.