Which of the Following Best Defines a Conversion Ratio

Which of the following best defines a conversion ratio?

A) An option that can be exercised at any time until its expiration date.
B) The right to buy an asset at a fixed price during a particular period of time.
C) The dollar amount of a bond's par value that is exchangeable for one share of stock.
D) The number of shares per bond received for conversion into stock.
E) The value of a convertible bond if it was immediately converted into common stock.