The answer to the given sentence is Option A, Countess.
As per the question, the sentence would have the male gender noun to be replaced by the feminine noun, without dropping the vowel, and then adding the syllable ‘-ess’. The male gender noun in the sentence, ‘Count’ is a term used for a person who rules a certain area, much like a King or a mayor. The feminine gender noun with the same meaning is ‘Countess’, that is Option A.
While Option B, Counting and option C, County, are not related to the male gender noun that is mentioned in the sentence, and are wrong answers. Hence, option A, Countess is the correct answer.