The correct answer is C. Markovnikov’s rule.
Markovnikov’s rule is an empirical rule that states that in the addition of an electrophile to an alkene, the electrophile will preferentially add to the carbon atom that has more hydrogen atoms. This is because the more hydrogen atoms a carbon atom has, the more electron-rich it is. The electrophile will therefore be attracted to the more electron-rich carbon atom.
Bredt’s rule is a rule that states that a double bond will not be formed between two carbon atoms that are part of a ring system if the ring would become strained as a result. This is because the double bond would cause the ring to be less stable.
Cornforth’s rules are a set of rules that describe the stereochemistry of certain reactions in organic chemistry. These rules are named after John Cornforth, who won the Nobel Prize in Chemistry in 1975 for his work on these rules.
Baldwin’s rules are a set of rules that describe the regioselectivity of certain reactions in organic chemistry. These rules are named after John Baldwin, who proposed them in 1976.