In several recent papers given to the Institute and Faculty of Actuaries attention has been focused on options in both the assets and the liabilities of a life office. The warnings that have been given about the concealed danger of options and the desirability which has been stressed of making adequate, if not severe, charges therefor are, it is hoped, sufficient justification for introducing a paper confined to the subject of annuity and cash options. The paper is limited to the development of the theory and to supplying tables to assist in the calculation of option costs in practice; questions of policy are considered to be beyond the scope of the paper.