Which of the following best describes a digraph?

A digraph is best described as a single sound represented by two letters. This definition captures the essence of what a digraph is in the context of phonics and reading. For example, in the word "chop," the "ch" represents a single sound, distinct from the individual sounds of "c" and "h" when considered separately.

This concept is important in understanding how letters combine to create unique sounds that are essential for decoding words. Digraphs can be found in both consonants and vowels, broadening the understanding of how letter combinations affect pronunciation.

The other options do not accurately represent the definition of a digraph. A sound blend of three consonants refers more to a cluster than a digraph. A sequence of two vowels may refer to a vowel team or diphthong, but is not classified as a digraph. Lastly, a single phoneme represented by multiple graphemes suggests different spelling representations of the same sound, which again does not match the specific definition of a digraph.