You drop the final e before adding a suffix to a base word when
the base word ends in ee and the suffix begins with a vowel.
the suffix begins with a vowel.
the suffix begins with a consonant.
the base word ends in ce or ge and the suffix begins with a or o

The correct answer that would complete the given statement above would be the second option. You drop the final e before adding a suffix to a base word when the suffix begins with a vowel. Vowel suffixes include -ance, -er, -ing, -able/ible, -est, -ed and -ation. For example, the base word "love". You drop the final "e" and add a vowel suffix like "lover" or "loving".