The following table lists prices of Amazon options in January $2018$ when Amazon stock was selling for $$1,400.$

Suppose that by January $2019,$ the price of Amazon could either rise from its January $2018$ level to $$1,4001\mathrm{.}20=$$$1,680\mathrm{.}00$ or fall to

$$1,\frac{400}{1\mathrm{.}20}=$$$1,166\mathrm{.}67.$

a$.$ What would be your percentage return on a January expiration call option with an exercise price of $$1,400$ if the stock price

rose? $($Round your answer to $2$ decimal places.$)$

b$.$ What would be your percentage return if the stock price fell? $($Negative value should be indicated by a minus sign.$)$

c$.$ Which is riskier: the stock or the option?