call_put_flag: 'c' for a call and 'p' for a put
spot: spot price
strike: strike price
time: time to maturity in years
rate: risk-free interest rate to the exercise date in percent
volatility: annualized volatility of the asset in percent for the period through to the exercise date
cost_of_carry: net cost of holding the underlying asset (for common stocks, the risk free rate less the dividend yield), defaults to 0
OPT_BS_CARRYCOST uses the Black-Scholes model to calculate the 'elasticity' of a European option struck at strike on an asset with spot price spot. The elasticity of an option is the rate of change of its price with respect to its cost_of_carry.
Elasticity is expressed as the rate of change of the option value, per 100% volatility.