Answer:
4) E
Explanation:
In the English language, when forming words with prefixes or suffixes attached to a word root, a combining vowel is often used to connect these elements. The most commonly used combining vowel is the letter "E." It acts as a bridge between the word root and the added affixes, facilitating pronunciation and making the word flow more smoothly. By using the letter "E" as a combining vowel, it helps to create words that are easier to pronounce and understand.