Which of the following conditions is NOT a requirement for the doubling rule to apply when adding a suffix?

In applying the doubling rule for adding certain suffixes to words, one of the key requirements is that the word must end with a single vowel followed by a single consonant. This allows for the final consonant to be doubled before the suffix is added, ensuring that the pronunciation stays intact and the stress pattern is preserved. Thus, the statement that the word must end in two vowels is not a requirement for the doubling rule to apply; rather, this configuration does not necessitate any doubling at all.

The correct conditions for the doubling rule typically involve single-syllable words that end in one vowel and one consonant, and usually a vowel suffix is also involved for the doubling to take effect. Therefore, option A stands out as it does not fulfill any of the necessary criteria for the doubling rule to be applicable.