Rule a: if a word ends in e and the suffix begins with a vowel, usually the e is dropped before the suffix is added.
rule b: when a word needs a vowel to its pronunciation, the e is retained when adding a suffix.
rule c: when a word needs a vowel to keep its meaning, the final e is retained.
rule d: the final e of the word is usually retained if the suffix begins with a consonant.

form a new word, following the rules given above.

advertise (-e) + -ing=

type the letter of the rule being followed, a, b, c, or d .

rule: