The article 'A' is used before singular, countable nouns that begin with a co...

The article 'A' is used before singular, countable nouns that begin with a consonant sound, while the article 'AN' is used before singular, countable nouns that begin with a vowel sound. However, some words may start with a consonant or vowel letter but have an initial sound that differs from the expected pattern.

Select the alternative that uses the article incorrectly.