Cytosine makes up 20% of a sample of DNA. Approximately, what percentage of the DNA in this sample will be thymine

The carbon cycle is best defined as a process in which a. carbon changes from inorganic forms to organic forms and back b. carbon is changed into other elements such as oxygen or nitrogen c. carbon is continually created from the sun’s energy by plants d. carbon is consumed and regenerated from other elements such as oxygen and nitrogen