C) the first few letters. This is because the dictionary goes in alphabetical order.
Hello. You didn't show which words are underlined, so I'll give you the grammatical name and function of all of them.
What: Pronoun. It has the function of referring to or replacing a noun, representing something, which does not have a specific name, but which needs to be represented in the sentence. The pronoun is a variable word.
To do: Verb. It has the function of representing an action, an activity that will be performed by something or someone.
Is: Verb. It has the ability to represent a state or occurrence.
Problem: Noun. It has the function of naming something or someone.
